Three-dimensional ceramic molding based on microstereolithography for the production of piezoelectric energy harvesters

We have developed a three-dimensional (3-D) process for molding piezoelectric ceramic elements that uses a master polymeric mold produced by microstereolithography. With this method, ceramic slurry is injected into a 3-D polymeric mold in a centrifugal casting process. The polymeric master mold is thermally decomposed so that complex 3D piezoelectric ceramic elements can be produced. To demonstrate the fabrication of 3-D piezoelectric ceramic elements, we produced a helically curved piezoelectric element that can convert multidirectional loads into a voltage. We confirmed that the piezoelectric element could generate a voltage by applying a load in both parallel and lateral directions in relation to the helical axis. The power output of 123 pW was obtained by applying the maximum load of 2.8 N at 2 Hz along the helical axis. The 3-D ceramic molding process is capable to produce a highly efficient 3-D piezoelectric energy harvester that can scavenge multidirectional vibration energy to generate electrical energy by optimizing its 3-D shape.