Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Charging ahead: University of Houston team revealing secrets of electricity-producing materials

Researchers press on in their mission to power nanodevices of tomorrow

Much like humans, materials are capable of some pretty remarkable things when they're placed under pressure. In fact, under the right conditions, materials can even produce electricity.

Driven by the vision of our society one day being basically self-propelled, a team of University of Houston scientists has set out to both amplify and provoke that potential in materials known as piezoelectrics, which naturally produce electricity when literally subjected to strain.

The goal is to use piezoelectrics to create nanodevices that can power electronics, such as cell phones, MP3 players and even biomedical implants.

"Nanodevices using piezoelectric materials will be light, environmentally friendly and draw on inexhaustible energy supplies," says associate professor Pradeep Sharma, one of the creative minds at the Cullen College of Engineering running two projects on piezoelectrics. "Imagine a sensor on the wing of a plane or a satellite. Do we really want to change its battery every time its power source gets exhausted? Hard-to-access devices could be self-powered."

Piezoelectric materials convert mechanical energy into electrical energy, Sharma explains.

"Indeed, gas lighters used in most homes are based on this," he says. "These future piezoelectric nanodevices will also generate an electrical current in response to mechanical stimuli. Then, the energy will be stored in batteries or, even better, in nanocapacitors for use when needed."

Although piezoelectrics have been used for many years, Sharma's team is exploring new possibilities by beefing up the effect in natural piezoelectrics. Doing so requires understanding the phenomenon that spurs piezoelectricity, known as "flexoelectricity."

"Flexoelectricity, at the nanoscale, allows you to coax ordinary material to behave like a piezoelectric one. Perhaps more importantly, this phenomenon exists in materials that are already piezoelectric. You can make the effect even larger," Sharma says.

For example, the piezoelectricity in barium titanate can be increased by 300 percent when the material is reduced to a 2-nanometer-beam and pressure is applied. "Thus, you'll take an ordinary piezoelectric material and really give it some juice," he says.

Sharma underscores the flexoelectric effect is a function of size – and the smaller the better, at least for generating piezoelectric power. Materials with nanoscale features – such as nanoscale thin plates stacked on each other or materials with particles or holes the size of a few nanometers – exhibit a much larger flexoelectric effect, he says.

Ramanan Krishnamoorti, chairman of the department of chemical and biomolecular engineering, is working with Sharma to embed classes of nanostructures in polymers to create unusual types of piezoelectrics.

Meanwhile, Sharma and professor Ken White recently reported that the electrical activity caused by flexoelectricity also affects a material's resiliency. They tested their theory – that the elasticity of a material would be quite altered by flexoelectricity-caused electrical activity – by poking the material with a sophisticated needle.

"We basically predicted that when you poke it, because of this electrical activity, depending upon how big a crater you create, your elastic behavior will change. It's not supposed to. Ordinarily, whether you make a big crater or small crater, if you calculate how stiff it is or soft it is, it'll give you the same answer – a constant," Sharma says.

White and Sharma conducted several experiments on single crystals of materials.

"By monitoring the stiffness of the material as the crater became larger and larger," White says, "we discovered a change in elasticity relative to size, which could only be explained by flexoelectric effect."

Though a fair amount of research on piezoelectrics has been done, White says, the fabrication of piezoelectric nanostructures remains challenging. The amount of power that can be harvested is still too low to actually power wearable devices, he says, unless efficient electric storage solutions, like nanocapacitors, also are conceived.

Sharma says he would like to see wasted energy be harvested from a variety of sources.

"In principle, any human activities – for example, walking, jumping, swimming – will produce a certain amount of energy," he says, and could be made into electricity by piezoelectric nanostructures in shoes or in backpacks.

White says it's a matter of controlling materials' structures to the point at which considerably more power can be harvested from common activities.

"An enormous benefit can be expected – in everything from soldiers in the field, to police on the street, to air and ground vehicles – in the form of locally powered devices," White explains.

Sharma says the environment contains plenty of waste energy that can be harnessed into useful energy to make ours a "self-powered autonomous society."

"Recent technological advances and breakthroughs play an important role toward achieving that goal, but we need to be patient," he says. "Quantum mechanics, the basis of modern electronics, was 'discovered' in the early 1900s. Think how long it has taken for us to exploit that."

About the University of Houston

The University of Houston, Texas' premier metropolitan research and teaching institution, is home to more than 40 research centers and institutes and sponsors more than 300 partnerships with corporate, civic and governmental entities. UH, the most diverse research university in the country, stands at the forefront of education, research and service with more than 36,000 students.

About the Cullen College of Engineering

The Cullen College of Engineering at UH has produced five U.S. astronauts, 10 members of the National Academy of Engineering, and degree programs that have ranked in the top 10 nationally. With more than 2,600 students, the college offers accredited undergraduate and graduate degrees in biomedical, chemical, civil and environmental, electrical and computer, industrial, and mechanical engineering. It also offers specialized programs in aerospace, materials, petroleum engineering and telecommunications.

For more information about UH, visit the university's Newsroom at

To receive UH science news via e-mail, visit

Angela Hopp | EurekAlert!
Further information:

More articles from Power and Electrical Engineering:

nachricht 'Super yeast' has the power to improve economics of biofuels
18.10.2016 | University of Wisconsin-Madison

nachricht Engineers reveal fabrication process for revolutionary transparent sensors
14.10.2016 | University of Wisconsin-Madison

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>