A flexible electrokinetic power generator derived from paper and ink for wearable electronics

Low-grade energy harvesting from the ambient environment promises to relieve the energy shortage in the remote regions or emergency needs. The reported materials employed for low-grade energy harvesting requires costly raw materials and highly technical skills, hindering the applications in isolated regions or after natural disasters. Herein, we report the use of commercial air-laid paper and carbon ink to harvest electrokinetic energy in the capillary flow. The paper-based electrokinetic power generator with size of 6 cm × 1 cm could continuously generate an output voltage of 0.35 V and current of 33.9 μA in the ambient condition (20 °C and 50% Relative Humidity). The output power could maintain for over 120 h. When connected in series and in parallel, the power generator with excellent flexibility could power some common electronic devices in the atmosphere, such as light-emitting diode, electronic calculator and watch. This work offers a rational approach to employing low-cost materials for ambient energy harvesting, thus advancing the application in portable and wearable electronic devices.