Highly Doped Polycrystalline Silicon Microelectrodes Reduce Noise in Neuronal Recordings In Vivo

Saha, Rajarshi; Jackson, Nathan; Patel, Chirag H.; Muthuswamy, Jit

doi:10.1109/tnsre.2010.2056389

Cited by 7 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The EIS results revealed that the doped, semi-metallic 3C-SiC conductors have impedance values approaching those of metals commonly used in implantable microelectrodes, such as gold, platinum, or tungsten, as well as highly doped polysilicon [59,60]. The average impedance for a surface area of 491 µm 2 was approximately 75% lower (165 kΩ vs. 675 kΩ at 1kHz) than previously reported for our 4H-SiC electrodes [33].…”

Section: Discussionmentioning

confidence: 65%

Fabrication of a Monolithic Implantable Neural Interface from Cubic Silicon Carbide

et al. 2019

View full text Add to dashboard Cite

One of the main issues with micron-sized intracortical neural interfaces (INIs) is their long-term reliability, with one major factor stemming from the material failure caused by the heterogeneous integration of multiple materials used to realize the implant. Single crystalline cubic silicon carbide (3C-SiC) is a semiconductor material that has been long recognized for its mechanical robustness and chemical inertness. It has the benefit of demonstrated biocompatibility, which makes it a promising candidate for chronically-stable, implantable INIs. Here, we report on the fabrication and initial electrochemical characterization of a nearly monolithic, Michigan-style 3C-SiC microelectrode array (MEA) probe. The probe consists of a single 5 mm-long shank with 16 electrode sites. An ~8 µm-thick p-type 3C-SiC epilayer was grown on a silicon-on-insulator (SOI) wafer, which was followed by a ~2 µm-thick epilayer of heavily n-type (n+) 3C-SiC in order to form conductive traces and the electrode sites. Diodes formed between the p and n+ layers provided substrate isolation between the channels. A thin layer of amorphous silicon carbide (a-SiC) was deposited via plasma-enhanced chemical vapor deposition (PECVD) to insulate the surface of the probe from the external environment. Forming the probes on a SOI wafer supported the ease of probe removal from the handle wafer by simple immersion in HF, thus aiding in the manufacturability of the probes. Free-standing probes and planar single-ended test microelectrodes were fabricated from the same 3C-SiC epiwafers. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed on test microelectrodes with an area of 491 µm2 in phosphate buffered saline (PBS) solution. The measurements showed an impedance magnitude of 165 kΩ ± 14.7 kΩ (mean ± standard deviation) at 1 kHz, anodic charge storage capacity (CSC) of 15.4 ± 1.46 mC/cm2, and a cathodic CSC of 15.2 ± 1.03 mC/cm2. Current-voltage tests were conducted to characterize the p-n diode, n-p-n junction isolation, and leakage currents. The turn-on voltage was determined to be on the order of ~1.4 V and the leakage current was less than 8 μArms. This all-SiC neural probe realizes nearly monolithic integration of device components to provide a likely neurocompatible INI that should mitigate long-term reliability issues associated with chronic implantation.

show abstract

Section: Discussionmentioning

confidence: 65%

Fabrication of a Monolithic Implantable Neural Interface from Cubic Silicon Carbide

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The key enabling chemistry involves hydrolysis of Si NMs upon immersion in biofluids, to yield end products that are biocompatible. The results presented here indicate that Si NMs, at high levels of doping 24 , can additionally serve as the neural recording electrodes themselves, as a stable, yet ultimately transient, measurement interface. In addition to their established bioresorbability, the nanoscale thicknesses of Si NMs, when deployed with thin substrates, interconnect metals and dielectrics, yield devices with levels of mechanical flexibility necessary for conformal contact and chronically stable interfaces with neural tissues.…”

mentioning

confidence: 80%

Bioresorbable silicon electronics for transient spatiotemporal mapping of electrical activity from the cerebral cortex

et al. 2016

View full text Add to dashboard Cite

Bioresorbable silicon electronics technology offers unprecedented opportunities to deploy advanced implantable monitoring systems that eliminate risks, cost and discomfort associated with surgical extraction. Applications include post-operative monitoring and transient physiologic recording after percutaneous or minimally invasive placement of vascular, cardiac, orthopedic, neural or other devices. We present an embodiment of these materials in both passive and actively addressed arrays of bioresorbable silicon electrodes with multiplexing capabilities, that record in vivo electrophysiological signals from the cortical surface and the subgaleal space. The devices detect normal physiologic and epileptiform activity, both in acute and chronic recordings. Comparative studies show sensor performance comparable to standard clinical systems and reduced tissue reactivity relative to conventional clinical electrocorticography (ECoG) electrodes. This technology offers general applicability in neural interfaces, with additional potential utility in treatment of disorders where transient monitoring and modulation of physiologic function, implant integrity and tissue recovery or regeneration are required.

show abstract

“…Silver, copper are known to be toxic, while platinum, gold are reported to be safe [ 88 ]. Also, ceramic material like highly doped poly silicon is used [ 89 ]. Recently, conductive polymers have been used as non-toxic materials, with poly 3,4-ethylenedioxythiophene (PEDOT) [ 90 , 91 ], polypyrrole (PPy) [ 92 ], and polyaniline (PANI) [ 93 ] as typical examples.…”

Section: Penetrating Electrode For In Vivo Applicationsmentioning

confidence: 99%

Recent Progress on Microelectrodes in Neural Interfaces

Kim

Lee

et al. 2018

Materials

View full text Add to dashboard Cite

Brain‒machine interface (BMI) is a promising technology that looks set to contribute to the development of artificial limbs and new input devices by integrating various recent technological advances, including neural electrodes, wireless communication, signal analysis, and robot control. Neural electrodes are a key technological component of BMI, as they can record the rapid and numerous signals emitted by neurons. To receive stable, consistent, and accurate signals, electrodes are designed in accordance with various templates using diverse materials. With the development of microelectromechanical systems (MEMS) technology, electrodes have become more integrated, and their performance has gradually evolved through surface modification and advances in biotechnology. In this paper, we review the development of the extracellular/intracellular type of in vitro microelectrode array (MEA) to investigate neural interface technology and the penetrating/surface (non-penetrating) type of in vivo electrodes. We briefly examine the history and study the recently developed shapes and various uses of the electrode. Also, electrode materials and surface modification techniques are reviewed to measure high-quality neural signals that can be used in BMI.

show abstract

Highly Doped Polycrystalline Silicon Microelectrodes Reduce Noise in Neuronal Recordings In Vivo

Cited by 7 publications

References 15 publications

Fabrication of a Monolithic Implantable Neural Interface from Cubic Silicon Carbide

Fabrication of a Monolithic Implantable Neural Interface from Cubic Silicon Carbide

Bioresorbable silicon electronics for transient spatiotemporal mapping of electrical activity from the cerebral cortex

Recent Progress on Microelectrodes in Neural Interfaces

Contact Info

Product

Resources

About