University of Houston (UH; Houston) scientists are studying flexoelectricity in an effort to make piezoelectric materials that could be used to power such electronic devices as biomedical implants. Currently used in commercial applications such as gas lighters in homes and actuators, the research team hopes to use the materials to create an lightweight, environmentally friendly energy supply for nanodevices.
Using their understanding of flexoelectricity, the team is experiementing at the nanoscale to make ordinary material exhibit the piezoelectric effect. Associate professor Pradeep Sharma and Ramanan Krishnamoorti, UH chair of the chemical and biomolecular engineering department, are working together to embed classes of nanostructures in polymers to create unusual types of piezoelectrics. The flexoelectric effect is mainly a function of size, and materials with nanoscale features exhibit a much larger flexoelectric effect, according to Sharma.
“You can make the effect even larger [in materials that are already piezoelectric],” Sharma says. The piezoelectricity in barium titanate, for example, can be increased by 300% when the material is reduced to a 2-nm beam and pressure is applied, he adds.
In addition to the challenge of fabricating these piezoelectric nanostructures, the team—and the technology—are hindered by the lack of methods for storing the electricity produced by the materials. The amount of power that can be harvested is still too low to actually power wearable devices, unless efficient electric storage solutions, like nanocapacitors, also are conceived, according to UH professor Ken White.
