Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Biological Interface Using Piezotronics: Resistive Switches Based on Piezoelectric Nanowires Allow Electrical Signals to be Produced from Mechanical Actions

An array of piezoelectrically modulated resistive memory (PRM) cells is shown being studied in an optical microscope.Credit: Gary Meek
An array of piezoelectrically modulated resistive memory (PRM) cells is shown being studied in an optical microscope.
Credit: Gary Meek

Abstract:
Taking advantage of the unique properties of zinc oxide nanowires, researchers have demonstrated a new type of piezoelectric resistive switching device in which the write-read access of memory cells is controlled by electromechanical modulation. Operating on flexible substrates, arrays of these devices could provide a new way to interface the mechanical actions of the biological world to conventional electronic circuitry.

Biological Interface Using Piezotronics: Resistive Switches Based on Piezoelectric Nanowires Allow Electrical Signals to be Produced from Mechanical Actions

Atlanta, GA | Posted on July 26th, 2011

The piezoelectrically modulated resistive memory (PRM) devices take advantage of the fact that the resistance of piezoelectric semiconducting materials such as zinc oxide (ZnO) can be controlled through the application of strain from a mechanical action. The change in resistance can be detected electronically, providing a simple way to obtain an electronic signal from a mechanical action.

"We can provide the interface between biology and electronics," said Zhong Lin Wang, Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "This technology, which is based on zinc oxide nanowires, allows communication between a mechanical action in the biological world and conventional devices in the electronic world."

The research was reported online June 22 in the journal Nano Letters. The work was sponsored by the Defense Advanced Research Projects Agency (DARPA), the National Science Foundation (NSF), the U.S. Air Force and the U.S. Department of Energy.

In conventional transistors, the flow of current between a source and a drain is controlled by a gate voltage applied to the device. That gate voltage determines whether the device is on or off.

The piezotronic memory devices developed by Wang and graduate student Wenzhuo Wu take advantage of the fact that piezoelectric materials like zinc oxide produce a charge potential when they are mechanically deformed or otherwise put under strain. These PRM devices use the piezoelectric charge created by the deformation to control the current flowing through the zinc oxide nanowires that are at the heart of the devices - the basic principle of piezotronics. The charge creates polarity in the nanowires - and increases the electrical resistance much like gate voltage in a conventional transistor.

"We are replacing the application of an external voltage with the production of an internal voltage," Wang explained. "Because zinc oxide is both piezoelectric and semiconducting, when you strain the material with a mechanical action, you create a piezopotential. This piezopotential tunes the charge transport across the interface - instead of controlling channel width as in conventional field effect transistors."

The mechanical strain could come from mechanical activities as diverse as signing a name with a pen, the motion of an actuator on a nanorobot, or biological activities of the human body such as a heart beating.

"We control the charge flow across the interface using strain," Wang explained. "If you have no strain, the charge flows normally. But if you apply a strain, the resulting voltage builds a barrier that controls the flow."

The piezotronic switching affects current flowing in just one direction, depending whether the strain is tensile or compressive. That means the memory stored in the piezotronic devices has both a sign and a magnitude. The information in this memory can be read, processed and stored through conventional electronic means.

Taking advantage of large-scale fabrication techniques for zinc oxide nanowire arrays, the Georgia Tech researchers have built non-volatile resistive switching memories for use as a storage medium. They have shown that these piezotronic devices can be written, that information can be read from them, and that they can be erased for re-use. About 20 of the arrays have been built so far for testing.

The zinc oxide nanowires, which are about 500 nanometers in diameter and about 50 microns long, are produced with a physical vapor deposition process that uses a high-temperature furnace. The resulting structures are then treated with oxygen plasma to reduce the number of crystalline defects - which helps to control their conductivity. The arrays are then transferred to a flexible substrate.

"The switching voltage is tunable, depending on the number of oxygen vacancies in the structure," Wang said. "The more defects you quench away with the oxygen plasma, the larger the voltage that will be required to drive current flow."

The piezotronic memory cells operate at low frequencies, which are appropriate for the kind of biologically-generated signals they will record, Wang said.

These piezotronic memory elements provide another component needed for fabricating complete self-powered nanoelectromechanical systems (NEMS) on a single chip. Wang's research team has already demonstrated other key elements such as nanogenerators, sensors and wireless transmitters.

"We are taking another step toward the goal of self-powered complete systems," Wang said. "The challenges now are to make them small enough to be integrated onto a single chip. We believe these systems will solve important problems in people's lives."

Wang believes this new memory will become increasingly important as devices become more closely connected to individual human activities. The ability to build these devices on flexible substrates means they can be used in the body - and with other electronic devices now being built on materials that are not traditional silicon.

"As computers and other electronic devices become more personalized and human-like, we will need to develop new types of signals, interfacing mechanical actions to electronics," he said. "Piezoelectric materials provide the most sensitive way to translate these gentle mechanical actions into electronic signals that can be used by electronic devices."

####

For more information, please click here

Contacts:
John Toon, Manager
Research News & Publications Office
Georgia Institute of Technology
75 Fifth Street, N.W., Suite 314
Atlanta, Georgia 30308 USA
Phone: 404-894-6986
Web: gtresearchnews.gatech.edu
Twitter: @gtresearchnews

Abby Robinson
404-385-3364

Copyright © Georgia Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Chip Technology

Quantum obstacle course changes material from superconductor to insulator December 1st, 2016

Bumpy surfaces, graphene beat the heat in devices: Rice University theory shows way to enhance heat sinks in future microelectronics November 29th, 2016

Scientists shrink electron gun to matchbox size: Terahertz technology has the potential to enable new applications November 25th, 2016

Uncovering the secrets of friction on graphene: Sliding on flexible graphene surfaces has been uncharted territory until now November 23rd, 2016

Memory Technology

New technology of ultrahigh density optical storage researched at Kazan University: The ever-growing demand for storage devices stimulates scientists to find new ways of improving the performance of existing technologies November 30th, 2016

A Tiny Machine: UCSB electrical and computer engineers design an infinitesimal computing device October 28th, 2016

How nanoscience will improve our health and lives in the coming years: Targeted medicine deliveries and increased energy efficiency are just two of many ways October 26th, 2016

Making the switch, this time with an insulator: Colorado State University physicists, joining the fundamental pursuit of using electron spins to store and manipulate information, have demonstrated a new approach to doing so, which could prove useful in the application of low-powe September 2nd, 2016

Nanoelectronics

Supersonic spray yields new nanomaterial for bendable, wearable electronics: Film of self-fused nanowires clear as glass, conducts like metal November 23rd, 2016

What a twist: Silicon nanoantennas turn light around: The theoretical results will allow scientists to design nanodevices with extraordinary features for use in optoelectronics November 21st, 2016

2-D material a brittle surprise: Rice University researchers finds molybdenum diselenide not as strong as they thought November 14th, 2016

UCR researchers discover new method to dissipate heat in electronic devices: By modulating the flow of phonons through semiconductor nanowires, engineers can create smaller and faster devices November 13th, 2016

Discoveries

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Announcements

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics/Energy storage

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

A Phone That Charges in Seconds? UCF Scientists Bring it Closer to Reality November 21st, 2016

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

Vesper a Finalist for Two ACE Awards: Ultimate Products and Innovator of the Year -- Industry’s first piezoelectric MEMS microphone and Vesper CTO Bobby Littrell recognized for prestigious electronics-industry awards November 10th, 2016

Nanobiotechnology

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Nanobiotix Provides Update on Global Development of Lead Product NBTXR3: Seven clinical trials across the world: More than 2/3 of STS patients recruited in the “act.in.sarc” Phase II/III trial: Phase I/II prostate cancer trial now recruiting in the U.S. November 28th, 2016

From champagne bubbles, dance parties and disease to new nanomaterials: Understanding nucleation of protein filaments might help with Alzheimer's Disease and type 2 Diabetes November 24th, 2016

Making spintronic neurons sing in unison November 18th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project