Electroacoustic Topological Insulator-Based Logic Devices

This award supports research that contributes new knowledge related to electroacoustic transistors and logic devices to be employed in transformative wave-based technologies, thereby promoting the progress of science, and advancing prosperity and welfare. If successful, these devices will enable materials and structures to carry out computation in situ, offloading computing burden from traditional central processing units (CPUs).

Furthermore, conventional electronics may not be suitable for use in extreme temperature, pressure and radiation conditions, and thus as envisioned in hybrid computing systems a portion of the computation may be offloaded to a mechanical device while the higher-level tasks can be carried out by a conventional CPU from a safe and/or shielded proximity. The studied acoustic transistors and logic devices have the potential to impact many electromechanical applications, such as structural switches for industry 4.0, embedded sensors for soft robots, and multiplexers and demultiplexers for communications in next-generation wearables.

The devices will operate using reconfigurable topological interface states, which can be dynamically introduced throughout the material system using piezoelectric transducers and switching circuits. Topological interface states are known for their robustness to disorder and back-scattering immune wave propagation, resulting in very low-loss communication, ideal for the planned acoustic logic.

Outreach efforts will introduce a large number of underrepresented students to the frontiers of research in physics of waves and electromechanical systems, which will in turn inspire a next generation of scientists and engineers.

This research aims to make fundamental contributions to the design, development and exploration of electroacoustic platforms for logic. It will achieve this goal by developing electroacoustic transistors using reconfigurable topological interface states and subsequently demonstrate logical operations leveraging transistor action using theoretical, computational, and experimental methods.

Such interface states are anticipated to open routes to commercially viable logic devices robust to inevitable fabrication disorder and defects. Akin to ubiquitous surface acoustic wave (SAW) devices, these electroacoustic hybrid logic devices may have advantages over their fully electronic counterparts in terms of size and cost, and are expected to be more efficient (e.g., low latency output) than software solutions which require analog to digital conversion and digital signal processing.

Reconfiguring a single multipurpose topological insulator structure will result in reorientation of topological pathways to produce output corresponding to various logical operations such as AND, OR and NAND.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.