Changing the way to design sensors
US engineers have 3D-printed piezoelectric materials.
If you use voice-activated software – like iphone’s Siri or voice-to-text – tiny, brittle pieces of crystal or ceramic are converting the vibrations of your voice to electric impulses.
Now, researchers at Virginia Tech University in the US have developed a method to custom-design materials that could replace the delicate crystal and ceramic that were previously the only materials able to convert pressure to electricity in what is known as the piezoelectric effect.
These materials are smart, and they can sense stress and monitor impact in any direction, says research leader Xiaoyu Zheng. “We can tailor the architecture to make them more flexible and use them, for instance, as energy harvesting devices, wrapping them around any arbitrary curvature. We can make them thick, and light, stiff or energy-absorbing.”
The previously available crystal and ceramic piezoelectric materials can only work in certain orientations, because of the atomic structure.
The 3D ink designed by Zheng’s team copies the natural “lattice” of the crystal but allows for the orientation to be changed around. The materials can be printed using UV light in thicknesses only a fraction of the diameter of a human hair.
The possibilities for use go well beyond voice activation. While previous piezoelectric materials were limited by their stiffness and delicacy – needing a clean room for manufacturing – the robustness and flexibility of the new process means Zheng and his team envisage using the materials as sensors for nearly anything.
A paper detailing the team’s work was published in the journal Nature Materials.