Piezoelectric materials — materials capable of transferring electrical charge when heat or pressure is applied — can be found in everything from mobile phones to greeting cards. Now, thanks to the work of Xiaoyu Zheng and his team at Virginia Tech, these materials could now be produced more economically using 3D printing techniques.
3D printing could also eliminate the shape and size restrictions inherent in traditional piezoelectric materials, which are typically regulated to clean room environments. And with piezoelectric materials becoming increasingly affordable and versatile, applications will expand; for example, smart materials may be used for tactile sensing, impact and vibration monitoring, and energy harvesting.
Unlike traditional piezoelectric materials, in which electric charge movements are prescribed by intrinsic crystals, the new 3D-printed materials allow users to prescribe and program voltage responses. This means they can be magnified, reversed, or suppressed (i.e., controlled and directed).
According to Zheng, this means piezoelectric materials could now be used as transducers and sensors offering enhanced flexibility and strength, as well as the ability to respond to more stimuli, such as vibrations and electric signals. Plus, the materials' ability to show a wider number of responses could be used to identify the location, magnitude, and direction of the impacts.
Current piezoelectric production is reliant on the natural lattice structure of the crystal being used. At the atomic level, this means that orientation is fixed. Zheng's team, however, has produced a substitute that is identical to the crystal’s structure yet allows the lattice orientation to be altered or designed according to the application’s needs.
The material that was developed is fives times more sensitive than current piezoelectric polymers, and is printed at a scale measuring fractions of the diameter of a human hair. These features could provide even greater flexibility.
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