A5004390474- Neuroscience and Neural Engineering
- EEG and Brain-Computer Interfaces
- Graphene research and applications
- Advanced Memory and Neural Computing
- Neural dynamics and brain function
- Graphene and Nanomaterials Applications
- Gas Sensing Nanomaterials and Sensors
- 2D Materials and Applications
- Muscle activation and electromyography studies
- Carbon Nanotubes in Composites
- Advancements in Semiconductor Devices and Circuit Design
- 3D Printing in Biomedical Research
- Analog and Mixed-Signal Circuit Design
- MXene and MAX Phase Materials
- Advanced Fluorescence Microscopy Techniques
- Electrochemical Analysis and Applications
- Molecular Junctions and Nanostructures
- Advanced Optical Sensing Technologies
- Transcranial Magnetic Stimulation Studies
- Spinal Cord Injury Research
- Boron and Carbon Nanomaterials Research
- Thin-Film Transistor Technologies
- Nanowire Synthesis and Applications
- Conducting polymers and applications
- Advanced Sensor and Energy Harvesting Materials
University of California, San Diego
2019-2025
BioSurfaces (United States)
2021-2022
Indian Institute of Technology Guwahati
2017-2019
Abstract Over the past decade, stereotactically placed electrodes have become gold standard for deep brain recording and stimulation a wide variety of neurological psychiatric diseases. Current electrodes, however, are limited in their spatial resolution ability to record from small populations neurons, let alone individual neurons. Here, we report on an innovative, customizable, monolithically integrated human-grade flexible depth electrode capable up 128 channels able at 10 cm tissue. This...
We report innovative scalable, vertical, ultra-sharp nanowire arrays that are individually addressable to enable long-term, native recordings of intracellular potentials. Stable amplitudes potentials from 3D tissue-like networks neurons and cardiomyocytes obtained. Individual electrical addressability is necessary for high-fidelity electrophysiological recordings. This study paves the way toward predictive, high-throughput, low-cost drug screening platforms.
Abstract Epidural electrical stimulation (EES) of the spinal cord is widely applied for pain management and as a possible route to functional restoration after injury. Currently, EES employs bulky, nonconformal paddle arrays with low channel counts. This limits effectiveness by requiring high currents, reduces selectivity muscle recruitment, requires subject‐specific designs accommodate varied neuroanatomy across patient population. Here, on thin‐film, high‐channel count microelectrode...
Abstract Durable and conductive interfaces that enable chronic high‐resolution recording of neural activity are essential for understanding treating neurodegenerative disorders. These implants require long‐term stability small contact areas. Consequently, they often coated with a blend polymers crosslinked to enhance durability despite the potentially deleterious effect crosslinking on mechanical electrical properties. Here grafting poly(3,4 ethylenedioxythiophene) scaffold,...
Electrophysiological stimulation has been widely adopted for clinical diagnostic and therapeutic treatments modulation of neuronal activity. Safety is a primary concern in an interventional design leveraging the effects electrical charge injection into tissue proximity target neurons. While modalities damage during have extensively investigated specific electrode geometries paradigms, comprehensive model that can predict electrochemical safety limits vivo doesn’t yet exist. Here we develop...
Abstract Electrophysiological recording and stimulation are the gold standard for functional mapping during surgical therapeutic interventions as well capturing cellular activity in intact human brain. A critical component probing brain is interface material at electrode contact that electrochemically transduces signals to from free charge carriers measurement system. Here, we summarize state-of-the-art array systems context of translation use stimulating activity. We leverage parametric...
Objective. Diagnostic and therapeutic electrical stimulation are increasingly utilized with the rise of neuromodulation devices. However, systematic investigations that depict practical clinical paradigms (bipolar, two-electrode configuration) to determine safety limits currently lacking. Further, safe charge densities were classically determined from conical sharp electrodes generalized for cylindrical (depth) flat (surface grid) completely ignoring geometric factors govern current...
Closed-loop neuromodulation promises to enhance treatment for movement disorders, pain, and epilepsy. Advancements in low-im-pedance, high-density recording grids [1] have paved the way low-noise neural systems with high spatial temporal resolution. However, a conventional signal path programmable gain amplifiers (PGAs) shared ADC [2] saturates during stimulation because of amplifier gain. Due fundamental tradeoff input high-pass cutoff frequency (for dc electrode offset elimination), it...
Abstract The lack of techniques for counter doping in two dimensional (2D) semiconductors has hindered the development p/n junctions, which are basic building blocks electronic devices. In this work, low‐energy argon ions used to create sulfur vacancies and subsequently “filled” with oxygen p‐doped MoS 2− x O . incorporation into 2 lattice hence band‐structure modification reveal nature p‐type doping. These changes validated by X‐ray photoelectron spectroscopy, ultraviolet Raman...
In this study, we have studied the interaction of Phosgene (COCl2) on two configurations Titanium doped Graphene Nanoribbons (GNR)- Armchair GNR and ZigZag GNR. We analyze changes in electronic structure substrate before after adsorption Phosgene, with help Density Functional Theory (DFT) calculations. The doping was assumed to be substitutional. gas molecule introduced multiple account for randomness incoming substrate. Our results indicate that atom causes a catalytic splitting C-Cl bond,...
This article presents a digitally-assisted multi-channel neural recording system. The system uses 16-channel chopper-stabilized Time Division Multiple Access (TDMA) scheme to record multiplexed signals into single shared analog front end (AFE). choppers reduce the total integrated noise across modulated spectrum by 2.4 × and 4.3 in Local Field Potential (LFP) Action (AP) bands, respectively. In addition, novel impedance booster based on Sign-Sign least mean squares (LMS) adaptive filter (AF)...
Abstract Human pluripotent stem cell (hPSC)-derived electrically excitable cells provide a unique window into development, but they remain immature partially due to the lack of chronic stimulation. Here, we fabricated electrospun polymer nanofibers containing light-reactive reduced graphene oxide (rGO) as part new classes on-demand, active biomaterials enhance function. Fiber size, stiffness, and electrical conductivity varied with rGO concentration, which impacted hPSC-derived cardiomyocyte...
In this work, we employed Density Functional Theory (DFT), to study the interactions between NO and CO with Ti-doped zigzag graphene nanoribbon (ZGNR) structures. Two types of doped structures are considered i.e. SV-ZGNR in which Ti replaces one carbon atom DV-ZGNR replacing two adjacent atoms. Our results indicate that ZGNR is better for gas adsorption as compared already reported 2-D sheet. Also structures, preferred over terms adsorption. The changes electronic after can be seen states....
We report a new physics-based model for dual-gate amorphous-indium gallium zinc oxide (a-IGZO) thin film transistors (TFTs) which we developed and fine-tuned through experimental implementation benchtop characterization. fabricated characterized variety of test patterns, including a-IGZO TFTs with varying gate widths (100-1000
In this study, we employed the density functional theory (DFT) to study interactions between gaseous air pollutants, including di-atomic (CO and NO), tri-atomic (CO2 HCN), poly-atomic (HCHO COCl2) species, Ti-doped zigzag graphene nanoribbon (ZGNR) structures. During this, two types of doped structures are considered, i.e., SV-ZGNR in which Ti replaces one carbon atom DV-ZGNR, adjacent atoms. All gases under consideration observed exhibit significant adsorption energy over ZGNR except COCl2...
In this study, we employed the density functional theory (DFT) to study interactions between gaseous air pollutants, including di-atomic (CO and NO), tri-atomic (CO2 HCN), poly-atomic (HCHO COCl2) species, Ti-doped zigzag graphene nanoribbon (ZGNR) structures. During this, two types of doped structures are considered, i.e., SV-ZGNR in which Ti replaces one carbon atom DV-ZGNR, adjacent atoms. All gases under consideration observed exhibit significant adsorption energy over ZGNR except COCl2...
Abstract Over the past decade, stereotactically placed electrodes have become gold standard for deep brain recording and stimulation a wide variety of neurological psychiatric diseases. Current electrodes, however, are limited in their spatial resolution ability to record from small populations neurons, let alone individual neurons. Here, we report on novel, reconfigurable, monolithically integrated human-grade flexible depth electrode capable up 128 channels able at 10 cm tissue. This thin,...
Intracellular access with high spatiotemporal resolution can enhance our understanding of how neurons or cardiomyocytes regulate and orchestrate network activity, this activity be affected pharmacology other interventional modalities. Nanoscale devices often employ electroporation to transiently permeate the cell membrane record intracellular potentials, which tend decrease rapidly extracellular potential amplitudes time. Here, we report innovative scalable, vertical, ultra-sharp nanowire...