Microbellows actuator
AssigneeCalifornia Institute of Technology
InventorsYu-Chong Tai, Xing Yang
Life of this patent
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Abstract
A micromachined multi-layered microbellows-style actuator capable of delivering larger deflections compared to a single layered flat membrane of comparable size. Anchor structures are disclosed that improve the strength of the microbellows membrane. A characterization apparatus is used to measure microbellows membrane performance. Thermopneumatic actuators having a resistive heater chip are also disclosed. The microbellows membrane is manufactured by alternating deposition of structural layers and sacrificial layers on a substrate. The structural layers can be made of silicon nitride and the sacrificial layers can be made of polysilicon. The substrate is etched from the back to form an opening exposing the sacrificial layers, and then the membrane is released by etching away the sacrificial layers.
Claims35
A method of fabricating a microbellows actuator membrane, comprising:
- obtaining a support substrate;
- growing a support substrate protectant layer on said support substrate;
- first depositing a first sacrificial layer on top of said support substrate protectant layer;
- second depositing a first structural layer on top of said first sacrificial layer;
- third depositing a second sacrificial layer on top of said first structural layer;
- patterning said second sacrificial layer to open a contact window between said first structural layer and a second structural layer;
- fourth depositing said second structural layer on top of said second sacrificial layer;
- patterning said second structural layer;
- fifth depositing a third sacrificial layer on top of said second structural layer;
- patterning said third sacrificial layer;
- sixth depositing a third structural layer on top of said third sacrificial layer;
- patterning said third structural layer;
- etching a back side of said support substrate and a portion of said support substrate protectant layer forming an opening;
- immersing said support substrate with said first, second, third sacrificial layers and said first, second, third structural layers in an etchant;
- removing said first, second, third sacrificial layer thereby releasing the microbellows actuator membrane.
Dependencies are inferred from the claim text.