Energy-Efficient
Integrated Circuits and Systems Laboratory
Dr. Meng's research focuses on analog/RF/mixed-signal integrated circuit design. At higher level, the research endeavors to develop innovative solutions that enable exciting new applications in biomedical implants, wearables, energy harvesting, Internet of Things (IoT) devices and beyond. The primary goal is to research and develop highly-efficient wireless links, novel energy-efficient microelectronics and energy harvesting technologies to enable miniaturization while maintaining the battery life despite of the slowly-scaling battery technology. Additonal goals are to develop innovative technologies to improve the life quality, especially for people with disabilities and disorders.
Our multidisciplinary research involves activities from basic science to modeling, simulations, prototyping, measurements and animal experiments. Representative research directions include:
Ultra-Low Power WiFi Backscatter Communication
WiFi is the most ubiquitous wireless networking technology for IoT in homes, offices, and businesses. However, the conventional WiFi transceivers requires 10s-to-100s of mW of power, this can be prohibitively high for emerging classes of IoT devices that desires small form factor and/or long battery life. This project is to develop ultra-low power WiFi backscatter RFICs that can directly communicate with exsiting WiFi infrastructures in a plug-n-play fashion, together with innovative energy harvesting technologies, the system is expected to achieve near-zero-net power operations.
[ISSCC, NSDI]
Magnetic Human Body Communication (mHBC)
Wireless connectivity is essential for wearables in body area network (BAN) to enable applications including health monitoring, entertainment, etc. Ideally, the form factor of such devices should be significantly reduced to comfortably fit within human anatomy. However, BLE as the conventional way of the BAN, shows severe path loss around the human body as opposed to free space senarios since the human body absorbs RF energy quite well at 2.4 GH. As a result, BLE transceivers often dominate the power consumption of wearable devices, keep the wearables larger than ideal, or require frequent charging or battery replacing. This project is to develop ultra-efficient BAN transceivers with high data rate and spectrum efficiency through magnetic human body channels which is proven to have the lowest path loss around human body among all approaches known. An additional goal is to tranform mHBC communication channel to low loss powering channel to delliver energy simultaneously to all wearables in the BAN.
[Potential Commercialization]
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Ultrasonically-Interrogated Miniaturized Implants for High-Resolution
Neural Recording/Stimulation System
High-resolution recording has the ability to help us understand human organ mechanisms while electric stimulation has shown potential to treat diseases that convential medical approaches were not able to (parkinson, seizure, etc.). While conventional wiring solutions have risks of discomfort or infection, wireless approaches have been investigated intensively for recent decades. Inductively interrogated systems are known for its high efficiency when the implants are in centimeter range, but become inefficient when reduced to millimeter or sub-mm range, especially for deeply implanted devices. In this project, we are developing a network of distributed, minimally invasive, ultrasonically interrogated implants, that are envisioned to be small, light, free-floating to minimize motion artifacts, tissue damage, and risk of infection.
[TBioCAS, TCASII, ISCAS, EMBC, BioCAS]
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Energy Harvesting for Wearables
The goal of this project is to develop "smart" energy harvesting integrated circuits that will be capable of simultaneously harvest energy from multiple energy sources around human body (motion, heat, light, etc) to extend the battery life of wearables or even enable 24/7 operations. The chips are expected to adaptively and dynamically reconfiguring their structures to compensate for environmental, resonant frequency, load changes, etc. Our past research has successfully developed a system that can harvest energy from weak multi-axial human motion using a custom inertial harvester with multiple flexible beams to enable wearables with 24/7 operation for vigilant healthcare monitoring (shown below).
[ISSCC, TBioCAS, Advanced Energy Materials]
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