Academia.eduAcademia.edu

Outline

Title
Abstract
Key Takeaways
Figures
Introduction
Printable Materials for Soft Robotics
Conclusions and Future Trends
References
FAQs
All Topics
Engineering
Materials Engineering

3D printing for soft robotics - a review

Profile image of Imran ShahImran Shah

2018, Science and technology of advanced materials

https://doi.org/10.1080/14686996.2018.1431862
visibility

…

description

20 pages

Abstract

Soft robots have received an increasing attention due to their advantages of high flexibility and safety for human operators but the fabrication is a challenge. Recently, 3D printing has been used as a key technology to fabricate soft robots because of high quality and printing multiple materials at the same time. Functional soft materials are particularly well suited for soft robotics due to a wide range of stimulants and sensitive demonstration of large deformations, high motion complexities and varied multi-functionalities. This review comprises a detailed survey of 3D printing in soft robotics. The development of key 3D printing technologies and new materials along with composites for soft robotic applications is investigated. A brief summary of 3D-printed soft devices suitable for medical to industrial applications is also included. The growing research on both 3D printing and soft robotics needs a summary of the major reported studies and the authors believe that this review a...

Key takeaways
sparkles

AI

  1. 3D printing revolutionizes soft robotics by enabling complex geometries and multi-material integration.
  2. The review highlights advancements in 3D printing technologies applicable to soft robot fabrication.
  3. Soft robots utilize materials like hydrogels and elastomers for flexibility and adaptability in design.
  4. Recent developments include soft robotic gloves aiding rehabilitation, showcasing practical applications in medicine.
  5. 3D printing fosters innovation in soft robotics, addressing challenges with smart materials and bio-integration.
Figures (9)
60 New topics/Others; 211 Scaffold / Tissue engineering / Drug delivery Soft robots have received an increasing attention due to their advantages of high flexibility anc safety for human operators but the fabrication is a challenge. Recently, 3D printing has beer used as a key technology to fabricate soft robots because of high quality and printing multiple materials at the same time. Functional soft materials are particularly well suited for soft robotic: due to a wide range of stimulants and sensitive demonstration of large deformations, hig motion complexities and varied multi-functionalities. This review comprises a detailed survey) of 3D printing in soft robotics. The development of key 3D printing technologies and nev materials along with composites for soft robotic applications is investigated. A brief summary of 3D-printed soft devices suitable for medical to industrial applications is also included. The growing research on both 3D printing and soft robotics needs a summary of the major reportec studies and the authors believe that this review article serves the purpose. 1. Introduction manufactured at low volumes in a cost-effective way. One of the main example of the design freedom offered is that conventional assemblies can be restructured in a single complex structure that could not be manufactured with the current manufacturing processes. Another driver of the 3D printing technology is that it is environmentally and ecologically favourable. 3D printing technologies and methods are growing frequently in terms of applica- tion and market share, spreading into various manufac- turing divisions, such as robotics, motorized, health and aerospace and are expected that this substantial growth will continue over the next few years.
60 New topics/Others; 211 Scaffold / Tissue engineering / Drug delivery Soft robots have received an increasing attention due to their advantages of high flexibility anc safety for human operators but the fabrication is a challenge. Recently, 3D printing has beer used as a key technology to fabricate soft robots because of high quality and printing multiple materials at the same time. Functional soft materials are particularly well suited for soft robotic: due to a wide range of stimulants and sensitive demonstration of large deformations, hig motion complexities and varied multi-functionalities. This review comprises a detailed survey) of 3D printing in soft robotics. The development of key 3D printing technologies and nev materials along with composites for soft robotic applications is investigated. A brief summary of 3D-printed soft devices suitable for medical to industrial applications is also included. The growing research on both 3D printing and soft robotics needs a summary of the major reportec studies and the authors believe that this review article serves the purpose. 1. Introduction manufactured at low volumes in a cost-effective way. One of the main example of the design freedom offered is that conventional assemblies can be restructured in a single complex structure that could not be manufactured with the current manufacturing processes. Another driver of the 3D printing technology is that it is environmentally and ecologically favourable. 3D printing technologies and methods are growing frequently in terms of applica- tion and market share, spreading into various manufac- turing divisions, such as robotics, motorized, health and aerospace and are expected that this substantial growth will continue over the next few years.
Figure 1. Examples of printed soft robots and soft devices. (a) Pre-strained polystyrene substrate with inkjet-printed hinges made of carbon black ink. (b) 3D-printed jumping soft robot. (c) 3D stereolithography-printed bat with curvature time lapse. (d) 4D-printed composite with swellableable hinges. (e) 4D-printed unfolded box composed of shape memory polymers. (f) A jumping soft robot with 3D-printed mould. (g) 4D printing of hydrogel composites for soft robotic applications. (h) A snake inspired soft robot with 3D-printed mould. (i) Multi-step 3D-printed octobot. (j) Pneumatic actuator for spinal compression and flextion with 3D-printed mould. (k) Embedded 3D printing of soft strain sensor for soft robots. (I) Multicore print head shell capacitive sensor. as motor driver, microcontroller and wireless communi- cation system [54]. Onal and Rus fabricated a soft robot through 3D printing technology that was bio-inspired from the shape and motion of a snake with the ability to undulate in a similar pattern to a real snake using the actuation power without human assistance. The as-fabricated soft snake robot was autonomous with onboard computation, control, power and actuation capabilities. The robot had four bidirectional actuators to create a wave through its entire body from head to tail. The time it took to fabricate the soft robotic snake was 14h with the ability to achieve an average locomo- tion speed of 19 mm s"! [55]. Homberg et al. applied the technique of 3D printing for the fabrication of a soft robotic hand with multi-fingers and ability to grip various solid objects such as a CD, paper, pen, soda can etc. Resistive bend sensors were installed in each finger nology, having high de electrically through SM purpose deformable ro forma A coi o distinguish between different objects. It had the ability 0 recognize a set of objects owing to the stored data from internal flex sensors. Each finger of the soft robotic hand had an independent sensing ability [56]. Umedachi et al. fabricated a soft worm robot by 3D printing tech- ble capability from rubber ike material. The reported soft worm does not require any fluidic or pneumatic actuators as they are powered s. The results of this study had important inferences for the ongoing research on soft animal locomotion and for designing other multi- bots [57]. Figure 1 shows exam- ples of 3D-printed soft robots for various applications.
Figure 1. Examples of printed soft robots and soft devices. (a) Pre-strained polystyrene substrate with inkjet-printed hinges made of carbon black ink. (b) 3D-printed jumping soft robot. (c) 3D stereolithography-printed bat with curvature time lapse. (d) 4D-printed composite with swellableable hinges. (e) 4D-printed unfolded box composed of shape memory polymers. (f) A jumping soft robot with 3D-printed mould. (g) 4D printing of hydrogel composites for soft robotic applications. (h) A snake inspired soft robot with 3D-printed mould. (i) Multi-step 3D-printed octobot. (j) Pneumatic actuator for spinal compression and flextion with 3D-printed mould. (k) Embedded 3D printing of soft strain sensor for soft robots. (I) Multicore print head shell capacitive sensor. as motor driver, microcontroller and wireless communi- cation system [54]. Onal and Rus fabricated a soft robot through 3D printing technology that was bio-inspired from the shape and motion of a snake with the ability to undulate in a similar pattern to a real snake using the actuation power without human assistance. The as-fabricated soft snake robot was autonomous with onboard computation, control, power and actuation capabilities. The robot had four bidirectional actuators to create a wave through its entire body from head to tail. The time it took to fabricate the soft robotic snake was 14h with the ability to achieve an average locomo- tion speed of 19 mm s"! [55]. Homberg et al. applied the technique of 3D printing for the fabrication of a soft robotic hand with multi-fingers and ability to grip various solid objects such as a CD, paper, pen, soda can etc. Resistive bend sensors were installed in each finger nology, having high de electrically through SM purpose deformable ro forma A coi o distinguish between different objects. It had the ability 0 recognize a set of objects owing to the stored data from internal flex sensors. Each finger of the soft robotic hand had an independent sensing ability [56]. Umedachi et al. fabricated a soft worm robot by 3D printing tech- ble capability from rubber ike material. The reported soft worm does not require any fluidic or pneumatic actuators as they are powered s. The results of this study had important inferences for the ongoing research on soft animal locomotion and for designing other multi- bots [57]. Figure 1 shows exam- ples of 3D-printed soft robots for various applications.
Figure 2. (a) Multi-material 3D printing system by Advanced Micro Mechatronics (AMM) Research Lab, Jeju National University, South Korea. (b) Photograph of the AMM’'s multi-material 3D printing system. (c) Soft omnidirectional actuator by AMM Lab. (d) (i) Fabricated soft-bot actuation of each leg at different time intervals. (ii) Model of actuation to generate movement at different time intervals. (iii) Finite-element displacement simulation results of one complete actuation cycle. (iv) Finite element strain simulation of one complete actuation cycle. A liquid resin is selectively photopolymerized in the SLA new ayer ing o process by a laser. After the printing first layer, a ayer is introduced and afterward cross-linked by ocal illumination. This process of depositing liquid resin by layer is repeated several times until the print- f chosen 3D object is finished. Various other novel additive manufacturing techniques such as continuous iquid interface production (CLIP), digital projection ithography (DLP) and two-photon polymerization In this section, we will present introduction of diverse fabrication techniques based on additive manufactur- ing to show its ability to produce simple and complex soft robots with various applications. In additive man- ufacturing, a computer-controlled transformation stage typically changes a pattern-generating device, either in the form of an ink-based print head or laser optics to fabricate the desired objects in a layer by layer pattern. During the process of additive manufacturing, patterned regions composed of powders, inks or resins are solidi- fied to produce the desired 3D shapes. These 3D-printed objects are a physical realization of the digital designs. Several basic additive manufacturing printing tech- niques have been presented since the introduction of 3D printing. The technology has advanced from making basic prototypes to fabricating finished products. The explicit solidification and patterning method used by a given additive manufacturing technique exhibits the minimum feature size that can be achieved and the sort of printable soft materials that can be used. The major differences in the available basic printing methods are mainly related to increasing printing speed, enhancing
Figure 2. (a) Multi-material 3D printing system by Advanced Micro Mechatronics (AMM) Research Lab, Jeju National University, South Korea. (b) Photograph of the AMM’'s multi-material 3D printing system. (c) Soft omnidirectional actuator by AMM Lab. (d) (i) Fabricated soft-bot actuation of each leg at different time intervals. (ii) Model of actuation to generate movement at different time intervals. (iii) Finite-element displacement simulation results of one complete actuation cycle. (iv) Finite element strain simulation of one complete actuation cycle. A liquid resin is selectively photopolymerized in the SLA new ayer ing o process by a laser. After the printing first layer, a ayer is introduced and afterward cross-linked by ocal illumination. This process of depositing liquid resin by layer is repeated several times until the print- f chosen 3D object is finished. Various other novel additive manufacturing techniques such as continuous iquid interface production (CLIP), digital projection ithography (DLP) and two-photon polymerization In this section, we will present introduction of diverse fabrication techniques based on additive manufactur- ing to show its ability to produce simple and complex soft robots with various applications. In additive man- ufacturing, a computer-controlled transformation stage typically changes a pattern-generating device, either in the form of an ink-based print head or laser optics to fabricate the desired objects in a layer by layer pattern. During the process of additive manufacturing, patterned regions composed of powders, inks or resins are solidi- fied to produce the desired 3D shapes. These 3D-printed objects are a physical realization of the digital designs. Several basic additive manufacturing printing tech- niques have been presented since the introduction of 3D printing. The technology has advanced from making basic prototypes to fabricating finished products. The explicit solidification and patterning method used by a given additive manufacturing technique exhibits the minimum feature size that can be achieved and the sort of printable soft materials that can be used. The major differences in the available basic printing methods are mainly related to increasing printing speed, enhancing
Table 1. Summary of 3D printing technology with respect to soft robots.
Table 1. Summary of 3D printing technology with respect to soft robots.
Figure 3. 3D Printing techniques used to fabricate soft robots. (i) A liquid resin is selectively photo-polymerized in the process of SLA by a laser. (ii) Inkjet printing is similar to SLA in many ways with a difference that a movable inkjet head is used in this technique to apply a photopolymer being activated by a UV lamp. (iii) The powder of metal material is rolled across a build platform and a laser is directed into the powder followed by rolling the powder over the top of as-deposited layer and this process keeps on repeating till the desired 3D object is completely fabricated. (iv) DIW is an alternative printing technique to FDM for additive manufacturing of desired objects under ambient conditions in which ink passes through a nozzle in a controlled manner. (v) Shape deposition modelling technology consists of several steps including deposition. The material in heterogeneous deposition is changed between each deposition process. (vi) Soft materials are printed in the form of a continuous filament in FDM method with a single layer being deposited at a time.
Figure 3. 3D Printing techniques used to fabricate soft robots. (i) A liquid resin is selectively photo-polymerized in the process of SLA by a laser. (ii) Inkjet printing is similar to SLA in many ways with a difference that a movable inkjet head is used in this technique to apply a photopolymer being activated by a UV lamp. (iii) The powder of metal material is rolled across a build platform and a laser is directed into the powder followed by rolling the powder over the top of as-deposited layer and this process keeps on repeating till the desired 3D object is completely fabricated. (iv) DIW is an alternative printing technique to FDM for additive manufacturing of desired objects under ambient conditions in which ink passes through a nozzle in a controlled manner. (v) Shape deposition modelling technology consists of several steps including deposition. The material in heterogeneous deposition is changed between each deposition process. (vi) Soft materials are printed in the form of a continuous filament in FDM method with a single layer being deposited at a time.
Figure 4. 3D-printed bio-medical soft robot. (a) 3D CAD model of the carotid artery. (b) 3D-printed scaled version of the carotid artery. (c) Traveling of omnidirectional robot inside carotid artery without controlled steering. (d) Demonstration of static steering of omnidirectional robot inside carotid artery. (e) Traveling of omnidirectional robot inside carotid artery [4].
Figure 4. 3D-printed bio-medical soft robot. (a) 3D CAD model of the carotid artery. (b) 3D-printed scaled version of the carotid artery. (c) Traveling of omnidirectional robot inside carotid artery without controlled steering. (d) Demonstration of static steering of omnidirectional robot inside carotid artery. (e) Traveling of omnidirectional robot inside carotid artery [4].
Table 2. 3D-printed in vitro and in vivo soft structures. A soft robotic sleeve mimicking the material properties and natural motion of the heart has been developed and tested in vivo on pigs [115]. The 3D-printed implant increases the ejection output in the hearts of pig cadav- ers. This device is attached conformal to the heart surface without causing any inflammation or injury. 3D-printed soft biological machines powered by actual muscles are the first step towards replacement with ful inside the body [116 the repair of damaged muscles or ly functional 3D-printed muscles . 3D-printed soft micro-bio-bots can be employed for in vivo monitoring of various condi- tions and disease. The se robots can travel through blood vessels and food track and reach the inaccessible areas of the human body [ 17,118]. They can provide infor- mation of the vitals in the vicinity though embedded sensors and can also d areas. Another form o can be used in endos easily steering them t eliver targeted drug to the affected f3D-printed soft robotic actuators copic monitoring and surgery by hrough the vessels owing to their soft form and multiple degrees of freedom in motion [119]. Table 2 summarizes the in vitro/vivo biological soft structures.
Table 2. 3D-printed in vitro and in vivo soft structures. A soft robotic sleeve mimicking the material properties and natural motion of the heart has been developed and tested in vivo on pigs [115]. The 3D-printed implant increases the ejection output in the hearts of pig cadav- ers. This device is attached conformal to the heart surface without causing any inflammation or injury. 3D-printed soft biological machines powered by actual muscles are the first step towards replacement with ful inside the body [116 the repair of damaged muscles or ly functional 3D-printed muscles . 3D-printed soft micro-bio-bots can be employed for in vivo monitoring of various condi- tions and disease. The se robots can travel through blood vessels and food track and reach the inaccessible areas of the human body [ 17,118]. They can provide infor- mation of the vitals in the vicinity though embedded sensors and can also d areas. Another form o can be used in endos easily steering them t eliver targeted drug to the affected f3D-printed soft robotic actuators copic monitoring and surgery by hrough the vessels owing to their soft form and multiple degrees of freedom in motion [119]. Table 2 summarizes the in vitro/vivo biological soft structures.

Related papers

Design and Development of a Multi-Functional Bioinspired Soft Robotic Actuator via Additive Manufacturing
Dimitrios Tzetzis

Biomimetics

The industrial revolution 4.0 has led to a burst in the development of robotic automation and platforms to increase productivity in the industrial and health domains. Hence, there is a necessity for the design and production of smart and multi-functional tools, which combine several cutting-edge technologies, including additive manufacturing and smart control systems. In the current article, a novel multi-functional biomimetic soft actuator with a pneumatic motion system was designed and fabricated by combining different additive manufacturing techniques. The developed actuator was bioinspired by the natural kinematics, namely the motion mechanism of worms, and was designed to imitate the movement of a human finger. Furthermore, due to its modular design and the ability to adapt the actuator’s external covers depending on the requested task, this actuator is suitable for a wide range of applications, from soft (i.e., fruit grasping) or industrial grippers to medical exoskeletons for...

View PDFchevron_right
3D printing of very soft elastomer and sacrificial carbohydrate glass/elastomer structures for robotic applications
Armita Hamidi

Materials & Design, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

View PDFchevron_right
Strengthening Effect of Flooding in 3D Printed Porous Soft Robotics Scaffolds
selçuk mıstıkoğlu

International Journal of 3D Printing Technologies and Digital Industry, 2021

This study aims to design and 3D print porous elements for soft robotic applications and test the stiffness changes when the cavities are filled with liquids. When an elastic element has porous scaffolds, the stiffness can be controlled by filling the cavities with a liquid. A gyroid structure is selected for the design and evaluation of the characteristics of elements. The stiffness of the element in both non-filled and liquid-filled modes is analyzed using FEM simulation Software in two modes where simple support with central loading and compressive uniform loading. A porous test structure is created and tested in these modes for observation of the stiffness change. Employing an FDM printer in this project enabled us to make our thoughts to reality. The results show that liquid-filling can be used as a stiffening method for porous scaffolds in soft robotic applications.

View PDFchevron_right
3D/4D-printed bending-type soft pneumatic actuators: fabrication, modelling, and control
Akif Kaynak

Virtual and Physical Prototyping

This article reviews soft pneumatic actuators (SPAs) that are manufactured entirely via additive manufacturing methods. These actuators are known as four-dimensional (4D)-printed SPAs and can generate bending motions in response to either pressurised or vacuum (negative pressure) air stimulus after fabrication. They are characterised by geometrical and material factors that determine their motion trajectory, and the force they exert on manipulated soft objects in delicate applications such as food handling and non-invasive surgery. Here, we review various 3D printers and materials used for the fabrication of the pressurised air bending-type SPAs. The reported approaches for modelling and control of these actuators are presented and compared. General discussions, as well as future directions and challenges of these actuators, are given.

View PDFchevron_right
Biomedical soft robots: current status and perspective
Turaj Ashuri

Biomedical Engineering Letters, 2020

This paper reviews the current status of soft robots in biomedical field. Soft robots are made of materials that have comparable modulus of elasticity to that of biological systems. Several advantages of soft robots over rigid robots are safe human interaction, ease of adaptation with wearable electronics and simpler gripping. We review design factors of soft robots including modeling, controls, actuation, fabrication and application, as well as their limitations and future work. For modeling, we survey kinematic, multibody and numerical finite element methods. Finite element methods are better suited for the analysis of soft robots, since they can accurately model nonlinearities in geometry and materials. However, their real-time integration with controls is challenging. We categorize the controls of soft robots as model-based and model-free. Model-free controllers do not rely on an explicit analytical or numerical model of the soft robot to perform actuation. Actuation is the ability to exert a force using actuators such as shape memory alloys, fluid gels, elastomers and piezoelectrics. Nonlinear geometry and materials of soft robots restrict using conventional rigid body controls. The fabrication techniques used for soft robots differ significantly from that of rigid robots. We survey a wide range of techniques used for fabrication of soft robots from simple molding to more advanced additive manufacturing methods such as 3D printing. We discuss the applications and limitations of biomedical soft robots covering aspects such as functionality, ease of use and cost. The paper concludes with the future discoveries in the emerging field of soft robots.

View PDFchevron_right
Design Considerations for 3D Printed, Soft, Multimaterial Resistive Sensors for Soft Robotics
Sebastian Lee

Frontiers in Robotics and AI, 2019

Sensor design for soft robots is a challenging problem because of the wide range of design parameters (e.g., geometry, material, actuation type, etc.) critical to their function. While conventional rigid sensors work effectively for soft robotics in specific situations, sensors that are directly integrated into the bodies of soft robots could help improve both their exteroceptive and interoceptive capabilities. To address this challenge, we designed sensors that can be co-fabricated with soft robot bodies using commercial 3D printers, without additional modification. We describe an approach to the design and fabrication of compliant, resistive soft sensors using a Connex3 Objet350 multimaterial printer and investigated an analytical comparison to sensors of similar geometries. The sensors consist of layers of commercial photopolymers with varying conductivities. We characterized the conductivity of TangoPlus, TangoBlackPlus, VeroClear, and Support705 materials under various conditions and demonstrate applications in which we can take advantage of these embedded sensors.

View PDFchevron_right

References (120)

  1. Duda T, Raghavan LV. 3D metal printing technology. IFAC-PapersOnLine 2016;49:103-110. DOI:10.1016/ j.ifacol.2016.11.111.
  2. Bikas H, Stavropoulos P, Chryssolouris G. Additive manufacturing methods and modeling approaches: a critical review. Int J Adv Manuf Technol. 2016;83:389- 405. DOI:10.1007/s00170-015-7576-2.
  3. Gul JZ, Yang B-S, Yang YJ, et al. In situ UV curable 3D printing of multi-material tri-legged soft bot with spider mimicked multi-step forward dynamic gait. Smart Mater Struct. 2016;25:115009. DOI:10.1088/0964-1726/25/11/115009.
  4. Ivanova O, Williams C, Campbell T. Rapid Prototyping Journal Additive manufacturing (AM) and nanotechnology: promises and challenges. Rapid Prototyp J. 2013;19:353-364. DOI:10.1108/RPJ-12- 2011-0127.
  5. Khorram Niaki M, Nonino F. Additive manufacturing management: a review and future research agenda. Int J Prod Res. 2016;7543:1-21. DOI:10.1080/00207543.2 016.1229064.
  6. Rosen DW. A review of synthesis methods for additive manufacturing. Virtual Phys Prototyp. 2016;1-13. DOI: 10.1080/17452759.2016.1240208.
  7. Snyder TJ, Andrews M, Weislogel M, et al. 3D systems' technology overview and new applications in manufacturing, engineering, science, and education, 3D print. Addit Manuf. 2014;1:169-176. DOI:10.1089/ 3dp.2014.1502.
  8. Vaezi M, Seitz H, Yang S. A review on 3D micro- additive manufacturing technologies. Int J Adv Manuf Technol. 2013;67:1721-1754. DOI:10.1007/s00170- 012-4605-2.
  9. Yadollahi A, Shamsaei N. Additive manufacturing of fatigue resistant materials: challenges and opportunities. Int J Fatigue. 2017;98:14-31. DOI:10.1016/ j.ijfatigue.2017.01.001.
  10. Chimene D, Lennox KK, Kaunas RR, et al. Advanced bioinks for 3D printing: a materials science perspective. Ann Biomed Eng. 2016;44:2090-2102. DOI:10.1007/ s10439-016-1638-y.
  11. Elahinia M, Shayesteh Moghaddam N, Taheri Andani M, et al. Fabrication of NiTi through additive manufacturing: a review. Prog Mater Sci. 2016;83:630- 663. DOI:10.1016/j.pmatsci.2016.08.001.
  12. Vaezi M, Chianrabutra S, Mellor B, et al. Multiple material additive manufacturing -part 1: a review. Virtual Phys Prototyp. 2013;8:19-50. DOI:10.1080/ 17452759.2013.778175.
  13. Choi J, Kwon OC, Jo W, et al. 4D printing technology: a review, 3d print. Addit Manuf. 2015;2:159-167. DOI: 10.1089/3dp.2015.0039.
  14. Khoo ZX, Teoh JEM, Liu Y, et al. 3D printing of smart materials: a review on recent progresses in 4D printing. Virtual Phys Prototyp. 2015;10:103-122. DOI:10.1080/17452759.2015.1097054.
  15. Zolfagharian A, Kouzani AZ, Khoo SY, et al. Evolution of 3D printed soft actuators. Sensors Actuators A Phys. 2016;250:258-272. DOI:10.1016/j.sna.2016.09.028.
  16. Elango N, Faudzi AAM. A review article: investigations on soft materials for soft robot manipulations. Int J Adv Manuf Technol. 2015;80(5-8):1027-1037. DOI: 10.1007/s00170-015-7085-3.
  17. Hines L, Petersen K, Lum GZ, et al. Soft actuators for small-scale robotics. Adv Mater. 2016:1603483. DOI: 10.1002/adma.201603483.
  18. Dordlofva C, Lindwall A, Törlind P. Opportunities and challenges for additive manufacturing in space applications. Proc Nord. 2016; Trondheim, Norway, 10th -12th August 2016;1:401-410. ISBN: 978-1- 904670-80-3.
  19. Goh GD, Agarwala S, Goh GL, et al. Additive manufacturing in unmanned aerial vehicles (UAVs): challenges and potential. Aerosp Sci Technol. 2016;63:140-151. DOI:10.1016/j.ast.2016.12.019.
  20. Gross BC, Erkal JL, Lockwood SY, et al. Evaluation of 3D printing and its potential impact on biotechnology and the chemical sciences. Anal Chem. 2014;86:3240- 3253. DOI:10.1021/ac403397r.
  21. Gul JZ, Yang YJ, Young Su K, et al. Omni directional multimaterial soft cylindrical actuator and its application as a steerable catheter. Soft Robot. 2017;4(3):224-240. soro.2016.0042. DOI:10.1089/ soro.2016.0042.
  22. Lifton VA, Lifton G, Simon S. Options for additive rapid prototyping methods (3D printing) in MEMS technology. Rapid Prototyp J. 2014;20:403-412. DOI: 10.1108/RPJ-04-2013-0038.
  23. Angrish A. A critical analysis of additive manufacturing technologies for aerospace applications. 2014 IEEE Aerosp Conf, Big Sky, MT, USA. 2014;2014:1-6. DOI: 10.1109/AERO.2014.6836456.
  24. Bhushan B, Caspers M. An overview of additive manufacturing (3D printing) for microfabrication. Microsyst Technol. 2017;23:1117-1124. DOI:10.1007/ s00542-017-3342-8.
  25. Boparai KS, Singh R, Singh H. Development of rapid tooling using fused deposition modeling: a review. Rapid Prototyp J. 2016;22:281-299. DOI:10.1108/RPJ- 04-2014-0048.
  26. Chen RK, Jin Y, Wensman J, et al. Additive manufacturing of custom orthoses and prostheses - a review. Addit Manuf. 2016;12:77-89. DOI:10.1016/ j.addma.2016.04.002.
  27. Yang S, Zhao YF. Additive manufacturing-enabled design theory and methodology: a critical review. Int J Adv Manuf Technol. 2015;80:327-342. DOI:10.1007/ s00170-015-6994-5.
  28. Engstrom DS, Porter B, Pacios M, et al. Additive nanomanufacturing -a review. J Mater Res. 2014;1- 25. DOI:10.1557/jmr.2014.159.
  29. Espalin D, Alberto Ramirez J, Medina F, et al. A review of melt extrusion additive manufacturing processes: I Process design and modeling. Rapid Prototyp J. 2014;20:192-204. DOI:10.1108/RPJ-01-2013-0012.
  30. Fera M, Fruggiero F, Lambiase A, et al. State of the art of additive manufacturing: review for tolerances, mechanical resistance and production costs. Cogent Eng. 2016;3:1261503. DOI:10.1080/23311916.2016.1 261503.
  31. Ford SLN. Additive manufacturing technology: potential implications for U.S. manufacturing competitiveness. J Int Commer Econ. 2014;6:1-35.
  32. Ford S, Despeisse M. Additive manufacturing and sustainability: an exploratory study of the advantages and challenges. J Clean Prod. 2016;137:1573-1587. DOI: 10.1016/j.jclepro.2016.04.150.
  33. Frketic J, Dickens T, Ramakrishnan S. Automated manufacturing and processing of fiber-reinforced polymer (FRP) composites: an additive review of contemporary and modern techniques for advanced materials manufacturing. Addit Manuf. 2017;14:69- 86. DOI:10.1016/j.addma.2017.01.003.
  34. Gong X, Anderson T, Chou K. Review on powder-based electron beam additive manufacturing technology. Manuf Rev. 2014;1:1-2. DOI:10.1051/mfreview/2014001.
  35. Guo N, Leu MC. Additive manufacturing: technology, applications and research needs. Front Mech Eng. 2013;8:215-243. DOI:10.1007/s11465-013-0248-8.
  36. Hedges M, Marin AB. 3D Aerosol Jet® Printing -adding electronics functionality to RP/RM. WHITEPAPER - optomec. 2012:14-15.
  37. Huang Y, Leu MC, Mazumder J, et al. Additive manufacturing: current state, future potential, gaps and needs, and recommendations. J Manuf Sci Eng. 2015;137:14001. DOI:10.1115/1.4028725.
  38. Onal CD, Rus D. Autonomous undulatory serpentine locomotion utilizing body dynamics of a fluidic soft robot. Bioinspir Biomim. 2013;8:26003. DOI: 10.1088/1748-3182/8/2/026003.
  39. Homberg BS, Katzschmann RK, Dogar MR, et al. Haptic identification of objects using a modular soft robotic gripper. Intell Robots Systems (IROS), 2015
  40. IEEE/RSJ Int Conf, Hamburg, Germany. 2015;1698- 1705.
  41. Umedachi T, Vikas V, Trimmer BA. Softworms: the design and control of non-pneumatic, 3D-printed, deformable robots. Bioinspir Biomim. 2016;11:25001. DOI: 10.1088/1748-3190/11/2/025001.
  42. Truby RL, Lewis JA. Printing soft matter in three dimensions. Nature 2016;540:371-378. DOI:10.1038/ nature21003.
  43. Chan V, Park K, Collens MB, et al. Development of miniaturized walking biological machines. Sci Rep. 2012;2:857. DOI:10.1038/srep00857.
  44. Chan V, Jeong JH, Bajaj P, et al. Multi-material bio- fabrication of hydrogel cantilevers and actuators with stereolithography. Lab Chip. 2012;12:88-98. DOI: 10.1039/C1LC20688E.
  45. Peele BN, Wallin TJ, Zhao H, et al. 3D printing antagonistic systems of artificial muscle using projection stereolithography. Bioinspir Biomim. 2015;10:55003. DOI:10.1088/1748-3190/10/5/055003.
  46. MacCurdy R, Katzschmann R, Kim Y, et al. Printable hydraulics: a method for fabricating robots by 3D co- printing solids and liquids. arXiv Prepr. arXiv1512.03744. 2015. Available from: http://arxiv.org/abs/1512.03744.
  47. Gul JZ, Yang B-S, Yang YJ, et al. In situ UV curable 3D printing of multi-material tri-legged soft bot with spider mimicked multi-step forward dynamic gait. Smart Mater Struct. 2016;25:115009. DOI: 10.1088/0964-1726/25/11/115009.
  48. Lin H-T, Leisk GG, Trimmer B. GoQBot: a caterpillar- inspired soft-bodied rolling robot. Bioinspir Biomim. 2011;6:26007. DOI:10.1088/1748-3182/6/2/026007.
  49. Rost A, Schadle S. The SLS-generated soft robotic hand -an integrated approach using additive manufacturing and reinforcement learning. 2013 12th Int Conf Mach Learn Appl, Miami Beach, Miami, FL, USA. IEEE 2013:215-220. DOI:10.1109/ICMLA.2013.44.
  50. Roppenecker DB, Pfaff A, Coy JA, et al. Multi arm snake-like robot kinematics. 2013 IEEE/RSJ Int Conf Intell Robot Syst, Tokyo, Japan. IEEE 2013;2013:5040- 5045. DOI:10.1109/IROS.2013.6697085.
  51. Guo SZ, Heuzey M, Therriault D. Solvent -cast direct - write microfabrication of thermoplastic-based nanocomposite structures. 19TH Int Conf Compos Mater, Montreal, Quebec, Canada. 2013:1-9.
  52. Lewis JA. Direct ink writing of 3D functional materials. Adv Funct Mater. 2006;16:2193-2204. DOI: 10.1002/adfm.200600434.
  53. Robinson SS, O'Brien KW, Zhao H, et al. Integrated soft sensors and elastomeric actuators for tactile machines with kinesthetic sense. Extrem Mech Lett. 2015;5:47-53. DOI:10.1016/j.eml.2015.09.005.
  54. Xu X, Cheng W, Dudek D, et al. Material modeling for shape deposition manufacturing of biomimetic components. Am Soc Mech Eng. 2000;DETC2000/D:1-10.
  55. Bailey SA, Cham JG, Cutkosky MR, et al. Biomimetic robotic mechanisms via shape deposition manufacturing. Robot Res 9th Int Symp. 1999:403-410.
  56. He Y, Wu Y, Fu JZ, et al. Developments of 3D printing microfluidics and applications in chemistry and biology: a review. Electroanalysis 2016;28:1658-1678. DOI:10.1002/elan.201600043.
  57. Liu W, Li Y, Liu J, et al. Application and performance of 3D printing in nanobiomaterials. J Nanomater. 2013;2013:1-7. DOI:10.1155/2013/681050.
  58. Patra S, Young V. A review of 3D printing techniques and the future in biofabrication of bioprinted tissue. Cell Biochem Biophys. 2016;74:93-98. DOI:10.1007/ s12013-016-0730-0.
  59. Tack P, Victor J, Gemmel P, et al. 3D-printing techniques in a medical setting: a systematic literature review. Biomed Eng Online. 2016;15:115. DOI:10.1186/s12938-016-0236-4.
  60. Martinez RV, Glavan AC, Keplinger C, et al. Soft actuators and robots that are resistant to mechanical damage. Adv Funct Mater. 2014;24:3003-3010. DOI: 10.1002/adfm.201303676.
  61. Tolley MT, Shepherd RF, Mosadegh B, et al. Untethered soft robot. Soft Robot. 2014;1:213-223. DOI: 10.1089/soro.2014.0008.
  62. Hong S, Sycks D, ai Chan HF, et al. 3D printing: 3D printing of highly stretchable and tough hydrogels into complex, cellularized structures. Adv Mater. 2015;27:4034. DOI:10.1002/adma.201570182.
  63. Culha U, Hughes J, Rosendo A, et al. Soft robotics: trends, applications and challenges. 2017. DOI: 10.1007/978-3-319-46460-2.
  64. Zhao H, O'Brien K, Li S, et al. Optoelectronically innervated soft prosthetic hand via stretchable optical waveguides. Sci Robot. 2016;1:eaai7529. DOI: 10.1126/scirobotics.aai7529.
  65. Wehner M, Truby RL, Fitzgerald DJ, et al. An integrated design and fabrication strategy for entirely soft, autonomous robots. Nature 2016;536:451-455. DOI: 10.1038/nature19100.
  66. Mosadegh B, Polygerinos P, Keplinger C, et al. Pneumatic networks for soft robotics that actuate rapidly. Adv Funct Mater. 2014;24:2163-2170. DOI: 10.1002/adfm.201303288.
  67. Martinez RV, Branch JL, Fish CR, et al. Robotic tentacles with three-dimensional mobility based on flexible elastomers. Adv Mater. 2013;25:205-212. DOI: 10.1002/adma.201203002.
  68. Song YS, Sun Y, Van Den Brand R, et al. Soft robot for gait rehabilitation of spinalized rodents. IEEE Int Conf Intell Robot Syst, Tokyo, Japan. 2013:971-976. DOI: 10.1109/IROS.2013.6696468.
  69. Umedachi T, Trimmer BA. Design of a 3D-printed soft robot with posture and steering control. 2014 IEEE Int Conf Robot Autom, Hong Kong, China. IEEE 2014:2874-2879. DOI:10.1109/ICRA.2014.6907272.
  70. Kim J, Alspach A, Yamane K. 3D printed soft skin for safe human-robot interaction. IEEE Int Conf Intell Robot Syst, Hamburg, Germany. 2015 Dec:2419-2425. DOI: 10.1109/IROS.2015.7353705.
  71. Bartlett NW, Tolley MT, Overvelde JTB, et al. A 3D-printed, functionally graded soft robot powered by combustion. Science (80-.). 2015;349:161-165. DOI: 10.1126/science.aab0129.
  72. Katzschmann RK, Marchese AD, Rus D. Hydraulic autonomous soft robotic fish for 3D swimming. In Chatila R, Hirzinger G, editors. Berlin, Heidelberg: Springer Berlin Heidelberg; 2016. p. 405-420. DOI: 10.1007/978-3-319-23778-7_27.
  73. Marchese AD, Katzschmann RK, Rus D. A recipe for soft fluidic elastomer robots. Soft Robot. 2015;2:7-25. DOI: 10.1089/soro.2014.0022.
  74. Robinson SS, O'Brien KW, Zhao H, et al. Integrated soft sensors and elastomeric actuators for tactile machines with kinesthetic sense. Extrem Mech Lett. 2015;5:47-53. DOI:10.1016/j.eml.2015.09.005.
  75. Ahn S-H, Lee K-T, Kim H-J, et al. Smart soft composite: an integrated 3D soft morphing structure using bend-twist coupling of anisotropic materials. Int J Precis Eng Manuf. 2012;13:631-634. DOI: 10.1007/s12541-012-0081-8.
  76. Cheng N, Ishigami G, Hawthorne S, et al. Design and analysis of a soft mobile robot composed of multiple thermally activated joints driven by a single actuator. 2010 IEEE Int Conf Robot Autom, Anchorage, AK, USA. IEEE 2010:5207-5212. DOI: 10.1109/ROBOT.2010.5509247.
  77. Polygerinos P, Wang Z, Galloway KC, et al. Soft robotic glove for combined assistance and at-home rehabilitation. Rob Auton Syst. 2015;73:135-143. DOI: 10.1016/j.robot.2014.08.014.
  78. Maeder-York P, Clites T, Boggs E, et al. Biologically inspired soft robot for thumb rehabilitation. J Med Device. 2014;8:20934. DOI:10.1115/1.4027031.
  79. Menguc Y, Park Y-L, Pei H, et al. Wearable soft sensing suit for human gait measurement. Int J Rob Res. 2014;33:1748-1764. DOI:10.1177/0278364914543793.
  80. Zhang Y, Kim WS. Highly sensitive flexible printed accelerometer system for monitoring vital signs. Soft Robot. 2014;1:132-135. DOI:10.1089/ soro.2014.0003.
  81. Connolly F, Walsh CJ, Bertoldi K. Automatic design of fiber-reinforced soft actuators for trajectory matching. Proc Natl Acad Sci. 2016:201615140. DOI: 10.1073/pnas.1615140114.
  82. Mutlu R, Alici G, in het Panhuis M, et al. 3D printed flexure hinges for soft monolithic prosthetic fingers. Soft Robot. 2016;3:120-133. DOI:10.1089/ soro.2016.0026.
  83. Muth JT, Vogt DM, Truby RL, et al. Embedded 3D printing of strain sensors within highly stretchable elastomers. Adv Mater. 2014:1-6. DOI:10.1002/ adma.201400334.
  84. Frutiger A, Muth JT, Vogt DM, et al. Capacitive soft strain sensors via multicore-shell fiber printing. Adv Mater. 2015;27:2440-2446. DOI:10.1002/ adma.201500072.
  85. Someya T, Kato Y, Sekitani T, et al. Conformable, flexible, large-area networks of pressure and thermal sensors with organic transistor active matrixes. Proc Natl Acad Sci USA. 2005;102:12321-12325. DOI: 10.1073/pnas.0502392102.
  86. Cho kJ, Koh JS, Kim S, et al. Review of manufacturing processes for soft biomimetic robots. Int J Precis Eng Manuf. 2009;10:171-181. DOI:10.1007/s12541-009- 0064-6.
  87. Ahn SH, Lee KT, Kim HJ, et al. Smart soft composite: an integrated 3D soft morphing structure using bend- twist coupling of anisotropic materials. Int J Precis Eng Manuf. 2012;13:631-634. DOI:10.1007/s12541- 012-0081-8.
  88. Lind JU, Busbee TA, Valentine AD, et al. Instrumented cardiac microphysiological devices via multimaterial three-dimensional printing. Nat Mater.2017;16:303-308. DOI:10.1038/nmat4782.
  89. Cham JG, Bailey SA, Clark JE, et al. Fast and robust: hexapedal robots via shape deposition manufacturing. Int J Rob Res. 2002;21:869-882. DOI: 10.1177/0278364902021010837.
  90. Dollar AM, Howe RD. Design and evaluation of a robust compliant grasper using shape deposition manufacturing. Dyn Syst Control Parts A B. ASME 2005:1403-1410. DOI:10.1115/IMECE2005-79791.
  91. Gafford J, Ding Y, Harris A, et al. Shape deposition manufacturing of a soft, atraumatic, and deployable surgical grasper. J Mech Robot. 2015;7:21006. DOI: 10.1115/1.4029493.
  92. Morrow J, Hemleben S, Menguc Y. Directly fabricating soft robotic actuators with an open-source 3-D printer. IEEE Robot Autom Lett. 2017;2:277-281. DOI:10.1109/LRA.2016.2598601.
  93. Carrico JD, Traeden NW, Aureli M, et al. Fused filament 3D printing of ionic polymer-metal composites (IPMCs). Smart Mater Struct. 2015;24:125021. DOI: 10.1088/0964-1726/24/12/125021.
  94. Onal CD, Rus D. A modular approach to soft robots. Proc IEEE RAS EMBS Int Conf Biomed Robot Biomechatronics, Rome, Italy. 2012:1038-1045. DOI: 10.1109/BioRob.2012.6290290.
  95. Mutlu R, Yildiz SK, Alici G, et al. Mechanical stiffness augmentation of a 3D printed soft prosthetic finger. 2016 IEEE Int Conf Adv Intell Mechatronics, Banff, Alberta, Canada. 2016:7-12. DOI:10.1109/AIM.2016.7576735.
  96. Yap HK, Ng HY, Yeow C-H. High-force soft printable pneumatics for soft robotic applications. Soft Robot. 2016;3:144-158. DOI:10.1089/soro.2016.0030.
  97. Rossiter J, Walters P, Stoimenov B. Printing 3D dielectric elastomer actuators for soft robotics. Proc Spie. 2009;7287:1-10. DOI:10.1117/12.815746.
  98. Cai J. 4D printing dielectric elastomer actuator based soft robots; 2016.
  99. Zarek M, Layani M, Cooperstein I, et al. 3D printing of shape memory polymers for flexible electronic devices. Adv Mater. 2016;28:4449-4454. DOI:10.1002/ adma.201503132.
  100. Yang Y, Chen Y, Wei Y, et al. 3D printing of shape memory polymer for functional part fabrication. Int J Adv Manuf Technol. 2016;84:2079-2095. DOI: 10.1007/s00170-015-7843-2.
  101. Zolfagharian A, Kouzani AZ, Khoo SY, et al. 3D printed hydrogel soft actuators. 2016 IEEE Reg 10 Conf, Marina Bay Sands, Singapore. IEEE. 2016;2016:2272- 2277. DOI:10.1109/TENCON.2016.7848433.
  102. Ozbolat IT, Hospodiuk M. Current advances and future perspectives in extrusion-based bioprinting. Biomaterials 2016;76:321-343. DOI: 10.1016/j.biomaterials.2015.10.076.
  103. Yuk H, Lin S, Ma C, et al. Hydraulic hydrogel actuators and robots optically and sonically camouflaged in water. Nat Commun. 2017;8:14230. DOI:10.1038/ncomms14230.
  104. Paik JK, Wood RJ. A bidirectional shape memory alloy folding actuator. Smart Mater Struct. 2012;21:65013. DOI:10.1088/0964-1726/21/6/065013.
  105. Umedachi T, Vikas V, Trimmer BA. Highly deformable 3-D printed soft robot generating inching and crawling locomotions with variable friction legs. IEEE Int Conf Intell Robot Syst, Tokyo, Japan. 2013:4590-4595. DOI: 10.1109/IROS.2013.6697016.
  106. Rus D, Tolley MT. Design, fabrication and control of soft robots. Nature 2015;521:467-475. DOI: 10.1038/nature14543.
  107. Schumacher CM, Loepfe M, Fuhrer R, et al. 3D printed lost-wax casted soft silicone monoblocks enable heart- inspired pumping by internal combustion. RSC Adv. 2014;4:16039. DOI:10.1039/C4RA01497A.
  108. Chan V, Jeong JH, Bajaj P, et al. Multi-material bio- fabrication of hydrogel cantilevers and actuators with stereolithography. Lab Chip. 2012;12:88-98. DOI:10.1039/c1lc20688e.
  109. Roche ET, Horvath MA, Wamala I, et al. Soft robotic sleeve supports heart function. Sci Transl Med. 2017:1-12.
  110. Raman R, Cvetkovic C, Bashir R. A modular approach to the design, fabrication, and characterization of muscle-powered biological machines. Nat Protoc. 2017;12:519-533. DOI:10.1038/nprot.2016.185.
  111. Petruska AJ, Nelson BJ. Soft micro-robots for military medicine. HDIAC J. 2017:25-27.
  112. Nelson BJ, Kaliakatsos IK, Abbott JJ. Microrobots for minimally invasive medicine. Annu Rev Biomed Eng. 2010;12:55-85. DOI:10.1146/annurev-bioeng- 010510-103409.
  113. Sliker LJ, Kern MD, Schoen JA, et al. Surgical evaluation of a novel tethered robotic capsule endoscope using micro-patterned treads. Surg Endosc Other Interv Tech. 2012;26:2862-2869. DOI:10.1007/s00464-012- 2271-y.
  114. Roche ET, Wohlfarth R, Overvelde JTB, et al. A bioinspired soft actuated material. Adv Mater. 2014;26:1200-1206. DOI:10.1002/adma.201304018.
  115. Lewis JA. Direct ink writing of 3D functional materials. Adv Funct Mater. 2006;16:2193-2204. DOI: 10.1002/adfm.200600434.
  116. Hockaday LA, Kang KH, Colangelo NW, et al. Rapid 3D printing of anatomically accurate and mechanically heterogeneous aortic valve hydrogel scaffolds. Biofabrication 2012;4:35005. DOI:10.1088/1758- 5082/4/3/035005.
  117. Wei Y, Chen Y, Ren T, et al. Variable stiffness robotic gripper based on integrated soft actuating and particle jamming. Soft Robot. 2016;3:134-143. DOI: 10.1089/soro.2016.0027.
  118. Bogue R. Flexible and soft robotic grippers: the key to new markets? Ind Robot An Int J. 2016;43(3):258-263.
  119. Rost A, Schädle S. The SLS-generated soft robotic hand -an integrated approach using additive manufacturing and reinforcement learning. Proc 2013 12th Int Conf Mach Learn Appl ICMLA 2013, Miami, FL, USA. 2013;1:215-220. DOI:10.1109/ICMLA.2013.44.
  120. Morrison RJ, Hollister SJ, Niedner MF, et al. Mitigation of tracheobronchomalacia with 3D-printed personalized medical devices in pediatric patients. Sci Transl Med. 2015;7:285ra64. DOI:10.1126/scitranslmed.3010825.

FAQs

sparkles

AI

What recent advancements have improved 3D printing for soft robots?add

The integration of techniques like UltiCast and photolithography has enabled quick and reliable soft robot fabrication. For example, Lewis' research on omnidirectional printing of liquid materials has advanced complexity in soft robotic design.

How do 3D-printed soft actuators compare in performance to traditional ones?add

3D-printed actuators exhibit an average error of about 5% in performance compared to molded actuators, as observed by Morrow et al. This similarity in functionality highlights the feasibility of 3D printing for soft robotics.

What materials have been recently identified as promising for soft robotics?add

Material classes such as dielectric elastomers, shape memory polymers, and hydrogels have shown potential for soft robotics applications. For instance, hydrogels have demonstrated hydraulic actuation capabilities ideal for soft robots.

What are the main benefits of using 3D printing in soft robotics?add

3D printing enables complex geometries with tailored material properties and reduces waste, offering design flexibility. The ability to integrate various materials within a single print enhances operational functionalities in soft robotics.

How are 3D-printed biological robots revolutionizing medical applications?add

In vivo applications like soft robotic sleeves have been shown to improve cardiac output in test subjects, indicating potential for future medical interventions. This demonstrates the ability of 3D-printed soft robots to interface effectively with biological systems.

About the author
Imran Shah
Wilbur Wright College, Graduate Student

Doctor | Fiction Writer | ActivistAs seen in: @medium @5pillarsnews @themuslimvibe @bbcasiannetwork.

Papers
151
Followers
3
View all papers from Imran Shaharrow_forward

Related papers

Indirect 3D and 4D Printing of Soft Robotic Microstructures
Gaston De BERNARDIS

Advanced Materials Technologies

today among small-scale roboticists is to substitute hard components with softer elements, including parts made from elastomers, hydrogels, macromolecular systems, and biomolecules. This paradigm shift in materials is a logical development from the locomotion and actuation point of view. Soft materials allow for more sophisticated movements such as deformation, shrinkage/swelling, and changes in morphology. [19,20] Additionally, soft materials display mechanical properties that are much closer to those of biological structures such as tissues, and they usually exhibit enhanced biocompatibility characteristics. Soft matter can also be programmed to biodegrade by the body's chemistry, for example, by enzymes or pH. [9,10] Consequently, the production of micro-and nanorobotic platforms from soft building blocks will advance the field of small-scale robotics (in terms of material constituents) toward medical applications. An impediment to the miniaturization of small soft components lies in the available manufacturing methods and their related limitations, which are mainly a result of the physicochemical nature of the soft material. In order to fabricate microand nanodevices with superior capabilities, the production of components with any conceivable shape is essential. To date, 3D printing (3DP) techniques have offered a wealth of opportunities for creating 3D structures with virtually unlimited shapes or materials. 3DP has also strongly impacted the field of robotics, by enabling the fabrication of soft robotic engines with sophisticated 3D continuous movements. Although substantial research has been devoted to the production of 3D printed small-scale robotic tools, these are typically made of nonresponsive, stiff materials [21-23] or, in the case of soft materials, their geometrical features are either rudimentary, or too large (from ≈200 µm to a few mm) to be used as biomedical micro or nanorobots. [24-26] Here, we propose a method that uses the capabilities of direct laser writing (DLW) [27] to produce complex 3D sacrificial templates for molding polymers that cannot be directly 3D printed at the microscale by any other technique. One of the first examples of using sacrificial templates obtained by DLW showed the fabrication of gold helices as photonic metamaterials as broadband circular polarizer. [28] Electrodeposition in DLW templates has also been utilized for the fabrication of

View PDFchevron_right
High-Force Soft Printable Pneumatics for Soft Robotic Applications
Hong Kai Yap

This work presents a novel technique for direct 3D printing of soft pneumatic actuators using 3D printers based on fused deposition modeling (FDM) technology. Existing fabrication techniques for soft pneumatic actuators with complex inner geometry are normally time-consuming and involve multistep processes. A low-cost open-source consumer 3D printer and a commercially available printing material were identified for printing soft pneumatic actuators with complex inner geometry and high degree of freedom. We investigated the material properties of the printing material, simulated the mechanical behavior of the printed actuators, characterized the performances of the actuators in terms of their bending capability, output forces, as well as durability, and demonstrated the potential soft robotic applications of the 3D printed actuators. Using the 3D printed actuators, we developed a soft gripper that was able to grasp and lift heavy objects with high pay–-to-weight ratio, which demonstrated that the actuators were able to apply high forces. To demonstrate the ability of the actuators to achieve complex movements, such as bidirectional bending movements, we also developed wearable hand and wrist exoskeletons that were able to assist finger flexion and wrist flexion–extension. The proposed technique is the first-in-class approach to directly 3D print airtight soft pneumatic actuators for soft robotic applications using FDM technology.

View PDFchevron_right
Review of manufacturing processes for soft biomimetic robots
Won-Shik Chu

International Journal of …, 2009

A robot is generally pictured as a machine with rigid bodies with rigid motion, characterized by their metal-like outer skin, with vivid image of nuts and bolts used to build these robots. This is quite different from the smooth motion and seamless smooth bodies of the human or ...

View PDFchevron_right
Fully 3D printed soft microactuators for soft microrobotics
Edwin Jager

Smart Materials and Structures, 2020

The feasibility of additive manufacturing actuating microstructures and microdevices with small dimension is presented. Using a custom-built extrusion 3D printer and CAD model of the device structure, bilayer microactuators driven by hydrogels are fabricated down to a size of 300 × 1000 μm2, with a minimum thickness of 30 μm. To explore the limitations of the 3D printing process, microactuators with a width of 300 μm and lengths ranging from 1000 to 5000 μm are manufactured and thereafter operated to demonstrate the feasibility of the process. Similarly, microrobotic devices consisting of a passive rigid body and flexible moving parts are 3D printed to illustrate the ease and versatility of the additive manufacturing technique to fabricate soft microgrippers or micromanipulators.

View PDFchevron_right
3D Printing Microactuators for Soft Microrobots
Edwin Jager

Soft Robotics

Current additive manufacturing, including three-dimensional (3D) and so-called four-dimensional printing, of soft robotic devices is limited to millimeter sizes. In this study, we present additive manufacturing of soft microactuators and microrobots to fabricate even smaller structures in the micrometer domain. Using a custom-built extrusion 3D printer, microactuators are scaled down to a size of 300 • 1000 lm 2 , with minimum thickness of 20 lm. Microactuators combined with printed body and electroactive polymers to drive the actuators are fabricated from computer-aided design model of the device structure. To demonstrate the ease and versatility of 3D printing process, microactuators with varying lengths ranging from 1000 to 5000 lm are fabricated and operated. Likewise, microrobotic devices consisting of a rigid body and individually controlled free-moving arms or legs are 3D printed to explore the microfabrication of soft grippers, manipulators, or microrobots through simple additive manufacturing technique.

View PDFchevron_right

Related topics

  • Materials Engineering
  • Additive Manufacturing

    • Cited by

    Improving Endurance of Pneumatic Linear Peristaltic Actuators
    Fernando Gomes Almeida

    Actuators

    Pneumatic linear peristaltic actuators can offer some potential advantages when compared with conventional ones. Low cost, virtually unlimited stroke and easy implementation of curved motion profiles are among those benefits. On the downside, these actuators suffer high mechanical stress, which leads to short endurance and increased leakage between chambers during the actuator lifetime. This paper contributes to this field by experimentally characterizing the life behavior of a prototype of a linear pneumatic peristaltic actuator where force—instead of displacement—between rollers is imposed. It is shown that the use of an imposed force configuration has a significant impact in the actuator life time. In fact, the proposed actuator configuration has an average endurance of up to 250% higher than the one previously presented in the literature. This result was obtained while maintaining almost zero leakage between chambers, despite the hose wear throughout the service life. Finally, t...

    View PDFchevron_right
    Virtual and Physical Prototyping of Reconfigurable Parallel Mechanisms with Single Actuation
    Marco Ceccarelli

    Applied Sciences

    The paper presents novel models of reconfigurable parallel mechanisms (RPMs) with a single active degree-of-freedom (1-DOF). The mechanisms contain three to six identical kinematic chains, which provide three (for the tripod) to zero (for the hexapod) uncontrollable DOFs. Screw theory is applied to carry out mobility analysis and proves the existence of controllable and uncontrollable DOFs of these mechanisms. Each kinematic chain in the synthesized mechanisms consists of planar and spatial parts. Such a design provides them with reconfiguration capabilities even when the driving link is fixed. This allows reproduction of diverse output trajectories without using additional actuators. In this paper, the model of a mechanism with six kinematic chains (hexapod) has been virtually and physically prototyped. The designing and assembling algorithms are developed using the detailed computer-aided design (CAD) model, which was further used to carry out kinetostatic analysis considering com...

    View PDFchevron_right
    Fiber Bragg Gratings in CYTOP Fibers Embedded in a 3D-Printed Flexible Support for Assessment of Human–Robot Interaction Forces
    Maria Pontes

    Materials

    We developed a flexible support with embedded polymer optical fiber (POF) sensors for the assessment of human–robot interaction forces. The supports were fabricated with a three-dimensional (3D) printer, where an acrylonitrile butadiene styrene (ABS) rigid structure was used in the region of the support in which the exoskeleton was attached, whereas a thermoplastic polyurethane (TPU) flexible structure was printed in the region where the users placed their legs. In addition, fiber Bragg gratings (FBGs), inscribed in low-loss, cyclic, transparent, optical polymer (CYTOP) using the direct-write, plane-by-plane femtosecond laser inscription method, were embedded in the TPU structure. In this case, a 2-FBG array was embedded in two supports for human–robot interaction force assessment at two points on the users’ legs. Both FBG sensors were characterized with respect to temperature and force; additionally, the creep response of the polymer, where temperature influences the force sensitiv...

    View PDFchevron_right
    Application of Additive Layer Manufacturing Technique on the Development of High Sensitive Fiber Bragg Grating Temperature Sensors
    Maria Pontes

    Sensors

    This paper presents the development of temperature sensors based on fiber Bragg gratings (FBGs) embedded in 3D-printed structures made of different materials, namely polylatic acid (PLA) and thermoplastic polyurethane (TPU). A numerical analysis of the material behavior and its interaction with the FBG sensor was performed through the finite element method. A simple, fast and prone to automation process is presented for the FBG embedment in both PLA and TPU structures. The temperature tests were made using both PLA- and TPU-embedded FBGs as well as an unembedded FBG as reference. Results show an outstanding temperature sensitivity of 139 pm/°C for the FBG-embedded PLA structure, which is one of the highest temperature sensitivities reported for FBG-based temperature sensors in silica fibers. The sensor also shows almost negligible hysteresis (highest hysteresis below 0.5%). In addition, both PLA- and TPU-embedded structures present high linearity and response time below 2 s. The res...

    View PDFchevron_right
    3D printing of graphene-based polymeric nanocomposites for biomedical applications
    Isabel Pinho

    Functional Composite Materials

    Additive manufacturing techniques established a new paradigm in the manufacture of composite materials providing a simple solution to build complex, custom designed shapes. In the biomedical field, 3D printing enabled the production of scaffolds with patient-specific requirements, controlling product architecture and microstructure, and have been proposed to regenerate a variety of tissues such as bone, cartilage, or the nervous system. Polymers reinforced with graphene or graphene derivatives have demonstrated potential interest for applications that require electrical and mechanical properties as well as enhanced cell response, presenting increasing interest for applications in the biomedical field. The present review focuses on graphene-based polymer nanocomposites developed for additive manufacturing fabrication, provides an overview of the manufacturing techniques available to reach the different biomedical applications, and summarizes relevant results obtained with 3D printed ...

    View PDFchevron_right
    580 California St., Suite 400
    San Francisco, CA, 94104
    © 2026 Academia. All rights reserved