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Xilin Liu

Publications and source records attributed to Xilin Liu.

39 records · Page 3Linked to original sources

A Fully Integrated Sensor-Brain-Machine Interface System for Restoring Somatosensation

Sensory feedback is critical to the performance of neural prostheses that restore movement control after neurological injury. Recent advances in direct neural control of paralyzed arms present new requirements for miniaturized, low-power sensor systems. To address this challenge, we developed a fully-integrated wireless sensor-brain-machine interface (SBMI) system for communicating key somatosensory signals, fingertip forces and limb joint angles, to the brain. The system consists of a tactile force sensor, an electrogoniometer, and a neural interface. The tactile force sensor features a novel optical waveguide on CMOS design for sensing. The electrogoniometer integrates an ultra low-power digital signal processor (DSP) for real-time joint angle measurement. The neural interface enables bidirectional neural stimulation and recording. Innovative designs of sensors and sensing interfaces, analog-to-digital converters (ADC) and ultra wide-band (UWB) wireless transceivers have been developed. The prototypes have been fabricated in 180nm standard CMOS technology and tested on the bench and in vivo. The developed system provides a novel solution for providing somatosensory feedback to next-generation neural prostheses.

q-bio.NC↗

Piezoelectric SPDT NEMS Switch for Complementary Logic

Off-state current leakage and switching delay has become the main challenge for continued complementary metal-oxide-semiconductor (CMOS) technology scaling. Previous work proposes a "see-saw" relay structure to mimic the operation of CMOS. This paper presents a novel single-pole double-throw (SPDT) switch structure based on AlN piezoelectric cantilever beam to improve the former "see-saw" relay structure. Geometry parameters are given and key switch parameters such as actuation voltage, switching time and contact force have been calculated and compared with previous "see-saw" relay structure. Analysis and design process is shown and micro-fabrication process is described as well.

physics.app-ph↗

Fractional spectral graph wavelets and their applications

One of the key challenges in the area of signal processing on graphs is to design transforms and dictionaries methods to identify and exploit structure in signals on weighted graphs. In this paper, we first generalize graph Fourier transform (GFT) to graph fractional Fourier transform (GFRFT), which is then used to define a novel transform named spectral graph fractional wavelet transform (SGFRWT), which is a generalized and extended version of spectral graph wavelet transform (SGWT). A fast algorithm for SGFRWT is also derived and implemented based on Fourier series approximation. The potential applications of SGFRWT are also presented.

cs.CV↗