The transistors and diodes add to the family of nanodevices developed by Wang and his research team, and could be combined into systems in which all components are based on the same zinc oxide material. The researchers have previously announced development of nanometer-scale generators that produce a voltage by converting mechanical motion from the environment, and nanowire sensors for measuring pH and detecting ultraviolet light.
"The family of devices we have developed can be joined together to create self-powered, autonomous and intelligent nanoscale systems," Wang said. "We can create complex systems totally based on zinc oxide nanowires that have memory, processing, and sensing capabilities powered by electrical energy scavenged from the environment."
Using strain-gated transistors fabricated on a flexible polymer substrate, the researchers have demonstrated basic logic operations including NOR, XOR and NAND gates and multiplexer/demultiplexer functions by simply applying different types of strain to the zinc oxide nanowires. They have also created an inverter by placing strain-gated transistors on both sides of a flexible substrate.
"Using the strain-gated transistor as a building block, we can build complicated logic," Wang added. "This is the first time that a mechanical action has been used to create a logic operation."
A strain-gated transistor is made of a single zinc oxide nanowire with its two ends the source and drain electrodes fixed to a polymer substrate by metal contacts. Flexing the devices reverses their polarity as the strain changes from compressive to tensile on opposite sides.
The devices operate at low frequencies the kind created by human interaction and the ambient environment and would not challenge traditional CMOS transistors for speed in conventional applications. The devices res
|Contact: John Toon|
Georgia Institute of Technology Research News