Microsensors that Function on the Basis of Surface and Wettability
Abstract
The displacement of non-wetting fluid droplets contained within capillaries that have axial profiles and are non-uniform can be used to accurately and reproducibility measure the forces acting upon these droplets. The position of droplets within such micro-sensors is dictated by surface tension, wettability, geometric configuration of the confining walls, and the forces acting upon the droplet. These micro-sensors can measure pressure and acceleration, and can also be made to operate as micro-valves, micro-switches, optical shutters, as well as other devices. They have no moving mechanical parts to wear out, and can theoretically endure high amounts of over-actuation and still return to initial levels of accuracy and precision without harm. The axial profiles of these shaped capillaries are easily fabricated using microtube technology developed at the Air Force Research Laboratory at Edwards Air Force Base. However, it is also possible to use non-circular shaped voids and still achieve similar capabilities with some limitations. These non-circular shaped voids can be manufactured using more conventional MEMS technologies such as photo lithography and LIGA.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 26, 2000
- Accession Number
- ADA408080
Entities
People
- P. Wapner
- W. Hoffman
Organizations
- Air Force Research Laboratory