A5032746121- Neuroscience and Neural Engineering
- Wireless Power Transfer Systems
- Energy Harvesting in Wireless Networks
- Advanced Memory and Neural Computing
- Wireless Body Area Networks
- EEG and Brain-Computer Interfaces
- Photoreceptor and optogenetics research
- Molecular Communication and Nanonetworks
- Neurological disorders and treatments
- Transcranial Magnetic Stimulation Studies
- Innovative Energy Harvesting Technologies
- Advanced Sensor and Energy Harvesting Materials
- Neural dynamics and brain function
- CCD and CMOS Imaging Sensors
- Virus-based gene therapy research
- Conducting polymers and applications
- Metamaterials and Metasurfaces Applications
- Microfluidic and Capillary Electrophoresis Applications
- Electrochemical sensors and biosensors
- Flood Risk Assessment and Management
- Modular Robots and Swarm Intelligence
- Gas Sensing Nanomaterials and Sensors
- Analytical Chemistry and Sensors
- Underwater Vehicles and Communication Systems
- Gaze Tracking and Assistive Technology
University of Florida
2023-2024
Johns Hopkins University
2016-2023
Massachusetts General Hospital
1993-2022
Harvard University
2020-2022
Hong Kong University of Science and Technology
2010-2015
University of Hong Kong
2010-2015
Abstract Ultra-compact wireless implantable medical devices are in great demand for healthcare applications, particular neural recording and stimulation. Current technologies based on miniaturized micro-coils suffer from low power transfer efficiency (PTE) not always compliant with the specific absorption rate imposed by Federal Communications Commission. Moreover, current reliant differential of voltage or across space require direct contact between electrode tissue. Here, we show an...
Wirelessly powered implants are increasingly being developed to interface with neurons in the brain. They often rely on microelectrode arrays, which limited by their ability cover large cortical surface areas and long-term stability because of physical size rigid configuration. Yet some clinical research applications prioritize a distributed neural over one that offers high channel count. One solution make scale, fully specifiable, electrical stimulation/recording possible, is disconnect...
An implant that can electrically stimulate neurons across different depths and regions of the brain currently does not exist as it poses a number obstacles need to be solved. In order address challenges, this paper presents concept "microbead," fully integrated wirelessly powered neural device allows for spatially selective activation tissue. The prototype chip is fabricated in 130-nm CMOS technology measures 200 μm × μm, which represents smallest remotely stimulator date. system validated...
This paper reviews and analyses the design of popular radio frequency energy harvesting systems proposes a method to qualitatively quantitatively analyze their circuit architectures using new square-wave approximation method. approach helps in simplifying analysis. Using this analysis, we can establish no load output voltage characteristics, upper limit on rectifier efficiency, maximum power characteristics rectifier. will help guide RF circuits for identification (RFIDs), Internet Things...
Abstract Wireless power transfer (WPT) within the human body can enable long-lasting medical devices but poses notable challenges, including absorption by biological tissues and weak coupling between transmitter (Tx) receiver (Rx). In pursuit of more robust efficient wireless power, various innovative strategies have emerged to optimize efficiency (PTE). One such groundbreaking approach stems from incorporation metamaterials, which shown potential enhance capabilities conventional WPT...
Objective. Noninvasive focal stimulation of deep brain regions has been a major goal for neuroscience and neuromodulation in the past three decades. Transcranial magnetic (TMS), instance, cannot target without activating overlying tissues poor spatial resolution. In this manuscript, we propose new concept that relies on temporal interference (TI) two high-frequency fields generated by electromagnetic solenoids.Approach. To illustrate concept, custom solenoids were fabricated optimized to...
A magnetoelectric antenna (ME) can exhibit the dual capabilities of wireless energy harvesting and sensing at different frequencies. In this article, a behavioral circuit model for hybrid ME antennas is described to emulate radio frequency (RF) operations during simulations. The work interfaced with CMOS harvester chip towards goal developing communication link fully integrated implantable devices. One role system receive pulse-modulated power from nearby transmitter, another sense transmit...
This paper presents a fully integrated RF energy harvester (EH) with 30% end-to-end power harvesting efficiency (PHE) and supports high output voltage operation, up to 9.3V, 1.07 GHz input under the electrode model for neural applications. The EH is composed of novel 10-stage self-biased gate (SBG) rectifier an on-chip matching network. SBG topology elevates gate-bias transistors in non-linear manner enable higher conductivity. design also achieves >20% PHE range 12-dB. was fabricated 65 nm...
Abstract Electrical stimulation via invasive microelectrodes is commonly used to treat a wide range of neurological and psychiatric conditions. Despite its remarkable success, the performance not sustainable since electrodes become encapsulated by gliosis due foreign body reactions. Magnetic overcomes these limitations eliminating need for metal-electrode contact. Here, we demonstrate novel microfabricated solenoid inductor (80 µm × 40 µm) with magnetic core that can activate neuronal...
This paper describes a miniaturized inductively powered neural stimulator chip. We propose solution to overcome the bulkiness of present implants by eliminating need for data decoders, digital control blocks and clocks. approach trades-off programmability, such as precise stimulus amplitude control, considerable reduction in chip area power consumption. The system is fabricated 0.18 μm CMOS process, consumes about 16 μW occupies merely 220 × 180 μm.
Over the past three decades, we have seen significant advances in field of wireless implantable medical devices (IMDs) that can interact with nervous system. To further improve stability, safety, and distribution these interfaces, a new class is being developed: single-channel, sub-mm scale, microelectronic devices. In this research, describe simple technique for fabricating assembling sub-mm, wirelessly powered stimulating implant. The implant consists an ASIC measuring 900 × 450 80 µm3,...
One of the main challenges for deployment sub-mm sized implantable device is limit on power that can be transmitted to these devices through inductive link. We first obtain optimal sizing coils in link and maximum delivered a 300 pm × using single transmitting coil at operating frequency 1.1 GHz. To increase power, we introduce optimize design phased array side taking into account safety limits. By adding achieve gain 1.43 dB while with addition four coils, increased by 4.3 reaches 10.6 μW.
This article describes the development of a radio frequency (RF) platform for electromagnetically modulated signals that makes use software-defined (SDR) to receive information from novel magnetoelectric (ME) antenna capable sensing low-frequency magnetic fields with ultra-low magnitudes. The is employed as part research and utilize miniaturized ME antennas integrated circuits neural recording wireless implantable devices. To prototype reception sensor, versatile Universal Software Radio...
We present a novel method for fabricating high-density carbon nanotube microelectrode array (MEA) chip. Vertically aligned nanotubes (VACNTs) were synthesized by microwave plasma-enhanced chemical vapor deposition and thermal deposition. The device was characterized using electrochemical experiments such as cyclic voltammetry, impedance spectroscopy potential transient measurements. Through-silicon vias (TSVs) fabricated partially filled with polycrystalline silicon to allow electrical...
Objective. Free-floating implantable neural interfaces are an emerging powerful paradigm for mapping and modulation of brain activity. Minuscule wirelessly-powered devices have the potential to provide minimally-invasive interactions with neurons in chronic research medical applications. However, these face a seemingly simple problem-how can they be placed into nervous tissue rapidly, efficiently essentially arbitrary location?Approach. We introduce novel injection tool describe controlled...
This work proposes solutions to the current bulky packaged neural implants. We describe next generation of miniaturized wirelessly powered interface that are distributed and free floating in nervous system. paper focuses on microassembly, hermetic packaging its effect inductive power link.
Abstract Ultra-compact wireless implantable medical devices (IMDs) are in great demand for healthcare applications, particular neural recording and stimulation. Current technologies based on miniaturized micro-coils suffer from low power transfer efficiency (PTE) not always compliant with the specific absorption rate imposed by Federal Communications Commission, particularly deep brain implantation where field attenuation tissue loss significant. Moreover, current reliant recordings of...
Most of the next-generation implantable medical devices that are targeting sub-mm scale form factors entirely powered wirelessly. The most commonly used wireless power transfer for ultra-small receivers is inductive coupling and has been so many decades. This might change with advent novel microfabricated magnetoelectric (ME) antennas which showing great potential as high-frequency receivers. In this paper, we compare these two delivery methods using operate at 2.52 GHz a surface area 0.043...
This paper highlights the challenges which exist in realizing miniaturized inductively powered devices that integrate μm-sized coils. As amount of energy harvested is directly proportional to effective area receiver coil, ultra-small coils receive very limited power and thus need be carefully optimized for a particular application. Apart from geometric design there are also many other factors impact maximum can on coil. These unique discussed addressed this work using fully integrated...
Optical recording of genetically encoded calcium indicator (GECI) allows neuroscientists to study the activity labeled neuron populations, but our current tools lack resolution, stability and are often too invasive. Here we present design concepts, prototypes, preliminary measurement results a super-miniaturized wireless image sensor built using 32nm Silicon-on-Insulator process. SOI process is optimal for applications, can further thin substrate reduce overall device thickness ~25μm operate...
This work introduces the smallest wirelessly powered neural implant to date. We provide experiment verification by successfully stimulating sciatic nerve of a rat. Power is deliverd over 1.7 GHz inductive link at distance 0.5 cm. A method also proposed generate biphasic current pulses without use controller. The entire system fabricated in 0.13 μm CMOS process and occupies merely 180 × μm.
Increasing the wireless power transfer efficiency (PTE) is crucial for implementing implantable medical devices (IMDs). The challenge in powering such implants stems from human brain tissue's elevated permittivity, conductivity, and mass density, which pose difficulties across high frequencies. This study introduces a metamaterial-based near-field (WPT) system. It evaluates its performance against traditional WPT systems with 36×36 mm transmitter 900×485 um receiver coil. size of...
This paper proposes a new single-turn coil design to improve Wireless Power Transfer (WPT) for brain implantable medical devices (IMDs). Our approach considers both near-field propagation and tissue interaction, primarily maximizing power transfer efficiency (PTE) while minimizing specific absorption rate (SAR). We present methods adjust the feed line using Grounded Coplanar Waveguide (GCPW) reduce impedance through parallelization of coils, resulting in reduction electric field (E-field)...