Georgia Institute of Technology has created logic circuits that can be used as the basis of nanometer-scale robotics and processors. The logic circuits are not as fast as those currently in use and based on CMOS. The researcher see the applications of the CMOS and nanowire technologies as being complementary. “The strain-gated logic devices are designed to interface with the ambient environment, which is associated with low-frequency mechanical actions, and the aim and targeting applications are different from those of conventional silicon devices which aim at speed.” Envisaged applications include nanorobotics, transducers, micromachines, human-computer interfacing, and microfluidics (where tiny channels carry various liquids, usually to be mixed for reaction tightly controlled ways).
The group intends to join the new strain-gated transducers to sensors and energy-drawing components they have previously prepared also from zinc oxide nanowires to make “self-sustainable, all-nanowire-based, multifunctional self-powered autonomous intelligent nanoscale systems
We present the first piezoelectric triggered mechanical-electronic logic operation using the piezotronic effect, through which the integrated mechanical actuation and electronic logic computation are achieved using only ZnO nanowires (NWs). By utilizing the piezoelectric potential created in a ZnO NW under externally applied deformation, strain-gated transistors (SGTs) have been fabricated. Using the SGTs as building blocks, universal logic components such as inverters, NAND, NOR, and XOR gates have been demonstrated for performing piezotronic logic calculations.
The SGI was fabricated by bonding two ZnO NWs laterally on a Dura-Lar film. The thickness of the Dura-Lar film is 0.5 mm. The ZnO NWs were synthesized via a physical vapor deposition method reported elsewhere and typically have diameters of 300 nm and lengths of 400 μm (Fig. 1a). The films were first cleaned with acetone, isopropyl alcohol and DI water by sonication, after which, the Dura-Lar films were dried by nitrogen gas blowing. One ZnO NW was placed flat on the top surface of the Dura-Lar film first using a probe station (Cascade Microtech, Inc.) under an optical microscope (Leica Microsystems, Inc.). Silver paint (Ted Pella, Inc.) was applied at both ends of the ZnO NW for electrical contacts. The second ZnO NW was placed on the bottom surface of the Dura-Lar film in the same way.