Leakage current and off-state power consumption is a major problem for nanometer scale electronics, which is one reason researchers are turning back to mechanical switches albeit at the micrometer-scale.
Nano electromechanical (NEM) switches could offer zero leakage, abrupt switching and high ON-current at low operating voltage. But the design of NEM switches for logic applications needs to address many challenges, such as device size, operational voltage and speed, robustness and contact resistance.
IBM Research (Zurich, Switzerland) has been exploring the design space for in-plane NEM switches. Because contact adhesion is one of limits on energy efficiency on such switches minimizing contact is important. IBM researchers have proposed a curved cantilever design for electrostatically actuated switches. The contact and actuation gap are not defined lithographically but by the thickness of a sacrificial layer.
The topic is also the subject of a collaborative research project between IBM and STMicroelectronics called NEMIAC.
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SEM image of a 15.5-micron switch with a stiffness of 4.5-N/m. Source: IBM Zurich
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IBM, ST go back to the future with nanorelay logic