Single-crystal cubic silicon carbide: An in vivo biocompatible semiconductor for brain machine interface devices

Abstract

Single crystal silicon carbide (SiC) is a wide band-gap semiconductor which has shown both bio- and hemo-compatibility [1-5]. Although single crystalline SiC has appealing bio-sensing potential, the material has not been extensively characterized. Cubic silicon carbide (3C-SiC) has superior in vitro biocompatibility compared to its hexagonal counterparts [3, 5]. Brain machine interface (BMI) systems using implantable neuronal prosthetics offer the possibility of bi-directional signaling, which allow sensory feedback and closed loop control. Existing implantable neural interfaces have limited long-term reliability, and 3C-SiC may be a material that may improve that reliability. In the present study, we investigated in vivo 3C-SiC biocompatibility in the CNS of C56BL/6 mice. 3C-SiC was compared against the known immunoreactive response of silicon (Si) at 5, 10, and 35 days. The material was examined to detect CD45, a protein tyrosine phosphatase (PTP) expressed by activated microglia and macrophages. The 3C-SiC surface revealed limited immunoresponse and significantly reduced microglia compared to Si substrate.

Enhancement of Cell Ingrowth, Proliferation, and Early Differentiation in a Three-Dimensional Silicon Carbide Scaffold Using Low-Intensity Pulsed Ultrasound

“…14,15 It has been also confirmed that SiC with 800-1000 mm pore size had good osteogenic and osteoconductive properties, and its promotion of adhesion, proliferation, and differentiation of primary culture osteoblasts in our previous research. [24][25][26] We used the same materials without simulating the natural bone.…”

Silicon Carbide Materials for Biomedical Applications

“…The material also is a semiconductor, and as such can be fabricated into electrical devices which can be used for sensing or signal reception and transmission. We have shown that the crystalline form of this material does not cause cytotoxic response in vitro and has not initiated chronic inflammatory response within animal models in vivo [41,44,57,128,155]. We have shown that it is a promising material to solve the longevity and reliability issues plaguing both continuous glucose monitors as well as neural implants [41,44,128,155].…”

“…Finally, it should be mentioned that graphene can be grown also on the cubic SiC polytype (3C-SiC), and in particular large area (more than hundreds of square microns) and highly [120] crystalline graphene can be obtained in the (111) orientation of this crystal which naturally accommodate the six-fold symmetry of graphene [125]. Cubic SiC possesses physicochemical properties which make it attractive for use in implantable devices [41]. Moreover, as it can be heteroepitaxially grown on Si it allows for an easy integration with Si electronics while providing a higher degree of biocompatibility than Si.…”

“…d An incubation device with PID controlled temperature and CO 2 saturation which will allow the MEA to be used for long term neuroscience experiments material uses most of the processing techniques available from the Si semiconductor device industry. Here we report some of the initial in vivo reactions from CNS microglia to an neural implant composed of 3C-SiC(100) [41,155].…”

“…At this stage it is useful to review some of the important biomedical devices that have been reported and use SiC materials. Indeed, SiC has been used in virtually every part of the human body, from a durable coating for bone prosthetics [38] and in dental applications [39], which cover the mechanical/structural biomedical use of SiC, to coatings for brain-machine-interface (BMI) devices [7,28,[40][41][42][43][44], myocardial heart probes [45,46] and finally non-fouling coatings for coronary heart stents [10,30,47]. A plethora of sensors have been reported and, at this point, it is sufficient to review the literature for a sampling of this important work [26].…”