Nanothermomechanical Logic Gates for Thermal Computing

Limited performance and reliability of electronic devices at extreme temperatures, intensive electromagnetic fields, and radiation found in space exploration missions (i.e., Venus & Jupiter planetary exploration, and heliophysics missions) and earth-based applications require the development of alternative computing technologies. Thermal computing, data processing based on heat instead of electricity, is proposed as a practical alternative and opens a new scientific area at the interface between thermal and computational sciences. We successfully developed thermal AND, OR and NOT logic gates, achieved through the coupling between near-field thermal radiation and MEMS thermal actuation. In the process, we developed two novel non-linear thermal expansion designs of microstructure silicon V-shaped chevron beams which were required to achieve the desired thermal AND gate operation. The successful design paves the way to develop full thermal logic circuits, so we show the design and simulation of a thermal calculator based on binary mathematical computations. This thermal calculator was able to perform the addition of two decimal numbers. Furthermore, we introduce the microfabrication and characterization of the thermal AND and OR logic gates. The thermal AND logic gate consists of two non-linear mechanisms using novel and ingenious chevron mechanisms consisting of spring-assisted reduction and cascading chevrons amplification for the reducing and the amplification mechanisms, respectively. The experimental results show that we achieved non-linearity ratios of thermal expansion β/α of 0.36 and 3.06 for the reducing and the amplification mechanisms, respectively. For the characterization of thermal AND logic gate, for the case when the two inputs were at Tmin (i.e., 0,0 case), we achieved an effectiveness of 10.7 % at a heat source temperature of 1549 K. For the thermal OR logic gate, for the cases of (1,0) and (0,1), we achieved an effectiveness of 25.3 % and 23.2 % at an input temperature of 1324 K and 1391 K, respectively. These results are significant breakthroughs in the field of thermal computation science and technology as they demonstrate thermal computing at high temperatures based on demonstrated and easy to manufacture NanoThermoMechanical logic gates