A MIT graduate student is changing the landscape of electromechanical switches.
Farnaz Niroui, an electrical engineering graduate student at MIT, has developed a squeezable nano electrochemical switch with quantum tunneling functions. Her development combats the longstanding problem of the switch locking in an “on” position due to metal-to-metal contacts sticking together.
The challenge of this permanent adhesion is called stiction, which often results in device failure. Niroui looks to solve this issue by creating electrodes with nanometer-thin separators.
She has effectively turned stiction from a problem into a solution.
“Initially the cantilever is fabricated with a relatively larger gap which is easier to fabricate, but then we modulate the surface adhesion forces to be able to cause a collapse between the cantilever and the support. As the cantilever collapses, the gap reduces to width much smaller tan patterned,” Niroui explained.
Her new technique, which is built off her earlier work showing a deign for squeezable switch (“squitch”), provides a general approach for developing nanoscale gaps.
This from MIT:
Building her switch on a silicon/silcon-oxide base, Niroui added a top layer of PMMA, a polymer that is sensitive to electron beams. She then used electron beam lithography to pattern the device structure and wash away the excess PMMA. She used a thermal evaporator to coat the switch structure with gold. Gold was the material of choice because it enables the thiolated molecules to self-assemble in the gap, the final assembly step.
The device has effectively established proof of the concept, but ill need improvements in the filler material for particle use.