SiC for Biomedical Applications

Biomedical Microdevices, 2013

Silicon carbide (SiC) has been around for more than 100 years as an industrial material and has found wide and varied applications because of its unique electrical and thermal properties. In recent years there has been increased attention to SiC as a viable material for biomedical applications. Of particular interest in this review is its potential for application as a biotransducer in biosensors. Among these applications are those where SiC is used as a substrate material, taking advantage of its surface chemical, tribological and electrical properties. In addition, its potential for integration as system on a chip and those applications where SiC is used as an active material make it a suitable substrate for micro-device fabrication. This review highlights the critical properties of SiC for application as a biosensor and reviews recent work reported on using SiC as an active or passive material in biotransducers and biosensors.

Micromachines, 2018

Intracortical neural interfaces (INI) have made impressive progress in recent years but still display questionable long-term reliability. Here, we report on the development and characterization of highly resilient monolithic silicon carbide (SiC) neural devices. SiC is a physically robust, biocompatible, and chemically inert semiconductor. The device support was micromachined from p-type SiC with conductors created from n-type SiC, simultaneously providing electrical isolation through the resulting p-n junction. Electrodes possessed geometric surface area (GSA) varying from 496 to 500 K μm². Electrical characterization showed high-performance p-n diode behavior, with typical turn-on voltages of ~2.3 V and reverse bias leakage below 1 nArms. Current leakage between adjacent electrodes was ~7.5 nArms over a voltage range of -50 V to 50 V. The devices interacted electrochemically with a purely capacitive relationship at frequencies less than 10 kHz. Electrode impedance ranged from 675 ...

2015

He has been an active researcher in the field of SiC Technology since 1992, when he pioneered the use of 6H-SiC for high-power optical switching. Since this early work, he has specialized in the development of various SiC processing methods, most notably CVD of 3C-SiC on Si. In the last decade he has focused on the use of 3C-SiC for biomedical applications and has been developing SiC-based continuous glucose monitoring systems and neural implants. He has over 150 published papers, 3 books, several book chapters and has several patents, awarded or pending, on the use of SiC for biomedical applications. He has held several visiting researcher/professor positions in Italy, Germany, France, and more recently Brazil.

2007

Cell-semiconductor hybrid systems are a potential centerpiece in the scenery of biotechnological applications. The selection and study of promising crystalline semiconductor materials for bio-sensing applications is at the basis of the development of such hybrid systems. In this work we introduce crystalline SiC as an extremely appealing material for bio-applications. For the first time we report biocompatibility studies of different SiC polytypes whose results document the biocompatibility of this material and its capability of directly interfacing cells without the need of surface functionalization.

Analytical Chemistry, 2011

Design, Test, Integration & Packaging of MEMS/ …, 2009

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Physics and Technology of Silicon Carbide Devices, 2012

Micromachines

An essential method to investigate neuromodulation effects of an invasive neural interface (INI) is magnetic resonance imaging (MRI). Presently, MRI imaging of patients with neural implants is highly restricted in high field MRI (e.g., 3 T and higher) due to patient safety concerns. This results in lower resolution MRI images and, consequently, degrades the efficacy of MRI imaging for diagnostic purposes in these patients. Cubic silicon carbide (3C-SiC) is a biocompatible wide-band-gap semiconductor with a high thermal conductivity and magnetic susceptibility compatible with brain tissue. It also has modifiable electrical conductivity through doping level control. These properties can improve the MRI compliance of 3C-SiC INIs, specifically in high field MRI scanning. In this work, the MRI compliance of epitaxial SiC films grown on various Si wafers, used to implement a monolithic neural implant (all-SiC), was studied. Via finite element method (FEM) and Fourier-based simulations, th...

Microelectronics Journal, 2007

Semi-insulating silicon carbide (SiC) is a fully processable semiconductors substrate that is commonly used as an alternative to conventional silicon (Si) in high-power applications. Here we examine the feasibility of using SiC as a substrate for the development of minimally invasive multi-sensor micro-probes in the context of organ monitoring during transplantation. In particular, we make a thorough comparison of Si and SiC material mechanical and electrical properties, and we extend this analysis to life-like situations using completed devices. Our results show that SiC outperforms Si in all respects, with a four times higher modulus of rupture for SiC devices and a 10-fold increase in the frequency range for electrical measurements in SiC-based probes. These results suggest that SiC should be preferably used over Si in all biomedical applications in which device breakage must be avoided or very precise electrical measurements are required. r

2012 International Conference on Biomedical Engineering (ICoBE), 2012

3C-SiC is currently under intense study as a potential material for implantable low power blood pressure sensing due to its biocompatibility. In this work, we present and discuss the fabrication processes for n-type 3C-SiC membranes using epitaxial SiC layers with thicknesses of 0.285 and 0.95 μm on Si substrates (650 μm). Membranes of n-type SiC with dimensions of 0.5×0.5 cm 2 were successfully fabricated using the described method for both thicknesses. We also report the fabrication of larger area membranes (1.5× 1.0 cm 2 ) using the 0.95 μm epitaxial layer. The thicker membrane was able to flex when probed using a micromanipulator electrical probe, however, the 0.285 μm membrane could not support the same small force. The ability to fabricate patterns of aluminum on the surface of the thicker membrane suggests future applications of large 3C-SiC membranes in microfabrication technology for biomedical microdevices. For electrical characterization, arrays of metal patterns were made on the 3C-SiC. Surface modification due to reactive ion etching (RIE) process had significant impact on the electrical properties of the sample. X-Ray Photoelectron Spectroscopy (XPS) was used to investigate surface modification due to RIE. The effect of reactive ion etching is expected to modify the biocompatibility of the 3C-SiC as a potential biomaterial.