High-Temperature-Operable Electromechanical Computing Units Enabled by Aligned Carbon Nanotube Arrays

Nano/micro-electromechanical (NEM/MEM) contact switches have great potential as energy-efficient and high-temperature-operable computing units to surmount those limitations of transistors. However, despite recent advances, the high-temperature operation of the mechanical switch is not fully stable nor repetitive due to the melting and softening of the contact material in the mechanical switch. Herein, MEM switches with carbon nanotube (CNT) arrays capable of operating at high temperatures are presented. In addition to the excellent thermal stability of CNT arrays, the absence of a melting point of CNTs allows the proposed switches to operate successfully at up to 550 °C, surpassing the maximum operating temperatures of state-of-the-art mechanical switches. The switches with CNTs also show a highly reliable contact lifetime of over 1 million cycles, even at a high temperature of 550 °C. Moreover, symmetrical pairs of normally open and normally closed MEM switches, whose interfaces are initially in contact and separated, respectively, are introduced. Consequently, the complementary inverters and logic gates operating at high temperatures can be easily configured such as NOT, NOR, and NAND gates. These switches and logic gates reveal the possibility for developing low-power, high-performance integrated circuits for high-temperature operations.