Navigation Links
3-dimensional view of 1-dimensional nanostructures
Date:1/6/2012

Just 100 nanometers in diameter, nanowires are often considered one-dimensional. But researchers at Northwestern University have recently reported that individual gallium nitride nanowires show strong piezoelectricity a type of charge-generation caused by mechanical stress in three dimensions.

The findings, led by Horacio Espinosa, James N. and Nancy J. Farley Professor in Manufacturing and Entrepreneurship at the McCormick School of Engineering and Applied Science, were published online Dec. 22 in Nano Letters.

Gallium nitride (GaN) is among the most technologically relevant semiconducting materials and is ubiquitous today in optoelectronic elements such as blue lasers (hence the blue-ray disc) and light-emitting-diodes (LEDs). More recently, nanogenerators based on GaN nanowires were demonstrated capable of converting mechanical energy (such as biomechanical motion) to electrical energy.

"Although nanowires are one-dimensional nanostructures, some properties such as piezoelectricity, the linear form of electro-mechanical coupling are three-dimensional in nature," Espinosa said. "We thought these nanowires should show piezoelectricity in 3D, and aimed at obtaining all the piezoelectric constants for individual nanowires, similar to the bulk material."

The findings revealed that individual GaN nanowires as small as 60 nanometers show piezoelectric behavior in 3D up to six times of their bulk counterpart. Since the generated charge scales linearly with piezoelectric constants, this finding implies that nanowires are up to six times more efficient in converting mechanical to electrical energy.

To obtain the measurements, researchers applied an electric field in different directions in single nanowire and measured small displacements, often in pico-meter (10-12 m) range. The group devised a method based on scanning probe microscopy leveraging high-precision displacement measurement capability of an atomic force microscope.

"The measurements were very challenging, since we needed to accurately measure displacements 100 times smaller than the size of the hydrogen atom," said Majid Minary, a postdoctoral fellow and the lead author of the study.

These results are exciting especially considering the recent demonstration of nanogenerators based on GaN nanowires, for powering of self-powered nanodevices.


'/>"/>
Contact: Megan Fellman
fellman@northwestern.edu
847-491-3115
Northwestern University
Source:Eurekalert  

Related biology technology :

1. Heated AFM tip allows direct fabrication of ferroelectric nanostructures on plastic
2. Intricate, curving 3-D nanostructures created using capillary action forces
3. High-speed filter uses electrified nanostructures to purify water at low cost
4. New security and medical sensor devices made possible by metallic nanostructures
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
3-dimensional view of 1-dimensional nanostructures
(Date:5/25/2016)... ... May 25, 2016 , ... The ... by the Office of the National Coordinator for Health IT (ONC) outlining a ... clinically relevant data were available when and where it was needed. The organization ...
(Date:5/25/2016)... UTAH. (PRWEB) , ... May 25, 2016 , ... WEDI, ... healthcare information exchange, today announced that Charles W. Stellar has been named by the ... interim CEO since January 2016. As an executive leader with more than 35 years ...
(Date:5/25/2016)... ... May 25, 2016 , ... ... Drug Administration (FDA) has granted the company’s orphan drug designation request covering BHV-4157 ... drug designation granted by the FDA. , Spinocerebellar ataxia is a rare, ...
(Date:5/24/2016)... 2016   MedyMatch Technology Ltd ., the data analytics ... decision support tools in the emergency room, announced today that ... Advanced Technology Industries (IATI) BioMed Conference. The ... 15th National Life Sciences and Technology Week, and is being ... in Tel Aviv, Israel . Gene ...
Breaking Biology Technology:
(Date:3/21/2016)... , March 22, 2016 ... with passcodes for superior security   ... leading provider of secure digital communications services, today announced ... technology and offer enterprise customers, particularly those in the ... recognition and voice authentication within a mobile app, alongside, ...
(Date:3/14/2016)... , March 14, 2016 NXTD ... growing mobile commerce market, announces the airing of a new ... starting the week of March 21 st .  The commercials ... including its popular Squawk on the Street show. --> ... on the growing mobile commerce market, announces the airing of ...
(Date:3/10/2016)... , March 10, 2016   Unisys Corporation ... and Border Protection (CBP) is testing its biometric identity ... San Diego to help identify certain non-U.S. citizens ... . The test, designed to help determine the efficiency and ... began in February and will run until May 2016. ...
Breaking Biology News(10 mins):