Flexible nanogenerators for self-powered touch and light sensor applications

Here we report a flexible piezoelectric nanodevices (nanogenerators) that can be utilized as both a touch sensor and a light sensor on a single platform. Based on the electron transporting and piezoelectric properties of ZnO, nanogenerators with a ZnO/conjugated polymer stacked structure was designed on a plastic substrate. Piezoelectric touch signals were demonstrated under independent and simultaneous operations with respect to photo-induced charges (photodetection). Different levels of piezoelectric output signals from different magnitude of touching pressures suggest new user-interface functions from our hybrid nanogenerators. From a signal controller, the decoupled performance of a hybrid nanogenerator as a touch sensor and a light sensor was confirmed. Our hybrid approach does not require additional assembling processes for such multiplex systems of a touch sensor and a light sensor since we utilize the coupled material properties of ZnO and output signal processing. Moreover, it should be noted that the hybrid nanogenerator can be operated in a self-powered mode without any power supply.