1. MEMS actuators /sensors

Research in this area is focused on designing energy efficient MEMS electrostatic actuators to achieve large out-of-plane displacements and rotations. We study static and dynamic behavior of actuators and how they affect their performance. We try to optimize the designs to maximize efficiency and minimize power consumptions. The MEMS actuators are attached to mirrors of about 1 mm size for potential applications in optical devices such as spectrometry, endoscopy, and optical coherence tomography. A recent design is an electrostatic 1mm diameter MEMS mirror that can move up to 40 microns out of plane at 60 V.

 Micromirror for optical applications

2. Energy Harvesting

Energy harvesting in the lab involves converting mechanical kinetic energy to electricity. Electricity is generated through piezoelectric, electromagnetic and triboelectric effects. Such energy harvesters find applications in structural health monitoring systems and biomedical sensors. The power generations are small in the range of milliwatts, though it is useful for emerging low power VLSI circuits. One interesting project involves exploiting nonlinear vibrations of cantilever resonators for improving efficiency of the energy harvesters from environmental vibration. Other projects under investigations include energy harvesting from triboelectric effect for an instrumented knee implant, and a self-powered ECG sensor.