Cascaded bimorph rotary actuator
US6698201B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2002 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Jun 5, 2022 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF03G7/064
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Linear bimorph actuators are cascaded together in serpentine array structures to achieve large angle rotary displacements. Bimorph units contain single material beams that remain straight when heated coupled with substantially parallel bilayer beams that deflect when heated, due to differential thermal expansion of the layers. For a bilayer beam, advantageous materials are gold on top of polysilicon. The angular deflection is amplified by cascading to achieve cumulative rotational displacements up to greater than 90 degrees. Successive beams can be connected electrically in series to provide a continuous current path for resistive joule heating. In various embodiments, the actuator is fully permanently anchored or releasably attached to a substrate, or at least a segment of the substrate is removed from beneath the actuator to prevent mechanical interference. Embodiments enable single and plural-axis rotational displacement and manipulation of payloads, for example microcomponents, mirrors, and pick-and-place devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.