Patent · US Expired

Valveless liquid microswitch

US5726404A · kind A · utility

361Cited by
10References
39Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 31, 1996
Grant dateMar 10, 1998
Priority date
Expiry dateMay 31, 2016

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/7303
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

This invention provides a valveless method and apparatus for high speed switching of liquid flow between intersecting microchannels. Liquid flow is controlled by manipulating external driving pressures. The switch comprises three intersecting microchannels, each having a liquid reservoir at its nonintersecting end for liquid inlet and outlet. It further includes applying a driving pressure to each reservoir switching the driving pressures. The microswitch of this invention operates to establish a liquid flow from a first channel to a second channel by applying a pressure differential between the first and second reservoirs, while simultaneously preventing flow into the third channel by applying a pressure to the third reservoir which equals the pressure at the junction of the three channels. By switching one or more driving pressures, the flow to the second channel can be stopped and the liquid flow redirected to the third channel. This invention further includes switches wherein more than three channels are included in the flow network, either intersecting in a single junction or in multiple junctions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.