Thermal actuator improvements: Tapering and folding

Michael J. Sinclair, Kerwin Wang

Research output: Contribution to journalConference articlepeer-review

7 Citations (Scopus)


Electrothermal actuation is not a popular technology for today's MEMS transducers due to its relatively slow response and large appetite for power. The large displacement with high force and low voltage gives reason to try to improve thermal actuator's operating characteristics. This paper describes some improvements to thermal actuators, mainly in increased output energy per actuator chip area and area utilization. The devices presented here are a variation of the chevron thermal actuator - one with two sets of thermally expanding beams pushing at a slight angle on either side of a suspended shuttle, causing it to be displaced parallel to the substrate. One improvement is to taper the thermal expansion beams so they exhibit a higher strain energy, allowing a larger thermal input power and hence more output mechanical power per beam. Another improvement is to move (fold) both sets of thermal beams to the same side of the shuttle so all are exerting force on the same side. The thermal expansion beams cause compression against the shuttle and work against one or two orthogonal cold beams in tension to produce an output force and displacement. This resembles a pseudo-bimorph array with the exception of having far fewer non-force-producing beams to bend.

Original languageEnglish
Pages (from-to)237-251
Number of pages15
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume5116 I
Publication statusPublished - 2003 Sep 19
EventSmart Sensors, Actuators, and MEMS - Maspalonas, Gran Canaria, Spain
Duration: 2003 May 192003 May 21

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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