A two-axis hybrid MEMS scanner incorporating electrothermal and electrostatic actuators

Abstract

A hybrid two-axis MEMS scanning mirror has been fabricated incorporating two different actuation mechanisms for its orthogonal rotation axes. The 2 mm diameter mirror is rotated about one axis using an electrostatic comb-drive for fast resonance movement and about the other axis using two out-of-plane electrothermal actuators. This hybrid actuation arrangement enables fast sweeps (at the mechanical resonant frequency) to be generated on one axis, with a slower sweep (from a few Hz to a few tens of Hz) to be generated on the orthogonal axis, raising the possibility of complex scan patterns being produced using relatively simple driving schemes. The characteristics of the first iteration of our device have been experimentally determined, and simultaneous driving of both actuation mechanisms has been demonstrated.