Is there a price to pay for computation in terms of energy? Although we immediately think about power-hungry computers based on transistors, which operate at efficiencies far from those dictated by the basic laws of physics, other ways to perform computations exist, for instance in the biological, quantum and mechanical domains. The fundamental question still remains, and to this point has been addressed by striking theoretical proposals – and conflicting experimental reports.
One obstacle to providing a satisfactory answer has been the lack of a precisely controllable, dynamic nanoscale system. Now, a research group led by Asst. Prof. Selim Hanay of the Department of Mechanical Engineering has developed a nanomechanical system that opens up avenues for exploring the deep connection between thermodynamics and computation. An article reporting their work was recently published in Physical Review Letters and, in recognition of its potential significance, highlighted by the journal as an editor’s selection and the Physics news website of American Physics Society.
The device developed by the Hanay research group has the shape of a slender beam with a nanoscale cross-section almost 300 times smaller than that of a strand of hair. The buckling of this beam can be controlled very precisely by electrostatic forces, making it possible for one-bit information to be encoded according to the direction in which the device buckles.
The device can thus be used as the building block for a nanomechanical computer. Although a mechanical computer would be slower and bulkier than its electronic counterpart, it could be operated under harsh conditions, such as nuclear radiation, extreme temperatures or possibly electronic warfare.
Ironically, the buckling mechanism that was used to encode information has long been regarded as catastrophic by civil and mechanical engineers. This work has now redefined buckling as an efficient mode of deformation at the nanoscale. Indeed, the new device can also be operated as a nanoscale positioning robot that can deflect objects sideways, making it of potential use in, for example, single-cell experiments that require precise control at the nanoscale.
Hanay research group members Selçuk Oğuz Erbil and Utku Hatipoğlu were the primary authors of the article. While the bulk of the research was conducted by the Hanay research group at Bilkent, Sabancı University SUNUM (via Dr. Cenk Yanık), Bilkent UNAM and Middle East Technical University MEMS provided nanofabrication support. Financial support for the project came from TÜBİTAK.
The article is available online at the Physical Review Letters website https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.046101; a news piece by American Physics Society is available at https://physics.aps.org/articles/v13/12, and a video of the device can be accessed at https://www.youtube.com/watch?v=EXk4vOJH4_4.