Optical Micromirror Actuation using Thermocapillary Effect in Microdroplets

This paper presents a simple means that utilizes surface tension gradient to cause droplet deformation, and to tilt micro-objects. Thermocapillary or Marangoni effect, and contact angle hysteresis are employed to control the droplet shape and position. The device consists of a microplate placed onto a microdroplet, and can produce a 6.5° tilting angle when actuated at 30 V. It shows the potential applications in scanning micromirror and display technology.