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Updated: Feb 1, 2026

Fabrication of a Bioactive, PCL-based "Self-fitting" Shape Memory Polymer Scaffold
Published on: October 23, 2015
Normally closed plunger-membrane microvalve self-actuated electrically using a shape memory alloy wire
Chaojun Cheng1, Ankitha Rajagopalan Nair2, Raviraj Thakur3
1Mechanical Engineering, Johns Hopkins University, Baltimore, USA.
Abstract:
Various microfluidic architectures designed for in vivo and point-of-care diagnostic applications require larger channels, autonomous actuation, and portability. In this paper, we present a normally closed microvalve design capable of fully autonomous actuation for wide diameter microchannels (tens to hundreds of μm). We fabricated the multilayer plunger-membrane valve architecture using the silicone elastomer, poly-dimethylsiloxane (PDMS) and optimized it to reduce the force required to open the valve. A 50-μm Nitinol (NiTi) shape memory alloy wire is incorporated into the device and can operate the valve when actuated with 100-mA current delivered from a 3-V supply. We characterized the valve for its actuation kinetics using an electrochemical assay and tested its reliability at 1.5-s cycle duration for 1 million cycles during which we observed no operational degradation.
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