School of Mechanical Engineering Gilad Berg

School of Mechanical Engineering Seminar
Wednesday, December 03, 2018 at 14:00
Wolfson Building of Mechanical Engineering, Room 206

Simulating photothermal actuation in resonant micro bridges

 Gilad Goldenberg

 MSc Student of Dr. Yoav Linzon

This work comes from the application need of optimizing the photothermal actuation in micro bridges that change their resonance frequencies with changes in mass due to gas absorption. The micro bridges are activated using 405[nm] (blue) laser close to resonance frequency, the actual bridge frequencies are sensed with red probe laser.

The research in this work is performed using Comsol Multiphysics, modeling the polysilicon micro bridges of various lengths (20 um, 30 um and 35 um) and their oscillation using thermal actuation in periodic and aperiodic actuation.

The research main results are:

1.    The expected displacements in 1.5um wide, 0.14um thick and 20um, 30um and 35 um long polysilicon bridges in the time domain.

2.    The expected maximum displacements in 1.5um wide, 0.14um thick and 20um, 30um and 35 um long polysilicon bridges in the frequency domain.

3.    The Q factors derived from the frequency domain analysis.

4.    An analysis of the bridge heating duty cycle effect on the maximum displacement.

5.    An analysis of unsynchronized activation.