Research

Bioelectronics Lab is the research lab of Dr. Hao Jiang.  This lab is part of the School of Engineering at San Francisco State University.  Dr. Jiang’s overarching research goals are to develop low-power, high-speed, energy-efficiency and small form-factor integrated circuit systems for biomedical and bio-inspired computing systems.  The research activities in Dr. Jiang’s lab are summarized in the following:

Bio-inspired Neuromorphic Computing System

Bio-inspired neuromorphic computing has been widely used to in many data-intensive applications, such as pattern recognition, data mining and synthesis. Dr. Hao Jiang’s overarching research goal is to develop energy-efficient small form-factor neuromorphic computing systems. He and his students are actively engaged in designing low-power and high-speed circuit systems that integrate the recent-developed nano-scale memristor crossbar array with the CMOS integrated circuits to overcome the efficiency issues associated with the traditional von Neumann computers.

Passive Wireless Sensing

Passive wireless sensing system that only consists of an inductor and a sensing capacitor resonator is gaining popularity in medicine due to it simplicity and high-reliability. By wirelessly monitoring its resonant frequency, the variation of the capacitance that correlates to local in-vivo pressure or pH value can be extracted.  The main challenge of a passive wireless sensing system is the trade off between the size of the coil and its maximal operating distance. By collaborating with Prof. Roy and Prof. Harrison in University of California at San Francisco (UCSF), Dr. Jiang and his students have developed a systematic approach to miniaturize the inductive coil yet maintaining the same operating distance.

Wireless Power Transfer

Biomedical implants demand more and more power to accommodate additional functionalities; however, the small size of an implant limits its battery capacity. Wireless power transfer can either charge the implant’s battery or support the implant’s activities by itself.  The technology could significantly increase the implant’s functionality, improve its performance, and prolong its lifespan without dramatically increasing its size. The inductive-coupling based wireless power transfer using two face-to-face coils is an efficient way to deliver power wirelessly.  Dr. Jiang and his students have developed a switching based rectifier that is able to efficiently boost and rectify the harvested low-voltage AC power to the usable high-voltage DC power.

Pulsed Ultra-Wide-Band (UWB) Circuits

Pulsed UWB is a desirable wireless communication protocol for implants. It needs much lower power for transmitting than for receiving, and its power consumption can dynamically correlate to the transmitting data rate. Both features are very desirable for implants. For most implants, reporting in-vivo data inside of the body to an external reader is one of the critical missions, and power is always scarce.  Dr. Jiang and his collaborators explored several circuit design techniques to further reduce the power consumption of the pulse generator in its transmitter.