Conference Paper

Self-actuated polymeric valve for autonomous sensing and mixing

Dept. of Micro & Nanotechnology, Denmark Tech. Univ., Lyngby, Denmark
DOI: 10.1109/SENSOR.2005.1497385 Conference: Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05. The 13th International Conference on, Volume: 2
Source: IEEE Xplore

ABSTRACT We present an autonomously operated microvalve array for chemical sensing and mixing, which gains the actuation energy from a chemical reaction on the valve structure. An 8-μm-thick flapper valve made in SU-8 is coated with stress-loaded Al on one side and Ti on the other side. The metal films keep the flapper in a flat, stress-balanced closed position. Upon contact with an analyte composed of a NaOH solution the Al film is etched from the valve surface unbalancing the surface stress and bending the flapper. A deflection of up to 45 μm is observed allowing for effective release of a green marker from a reservoir. Calculations reveal that valve operation with stress originating from biochemical processes will require considerable enhancement of the actuation efficiency.

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