We report on a flexible triboelectric nanogenerator (FTENG) designed using polydimethylsiloxane (PDMS) and aluminium (Al) combinations to convert ambient mechanical energy into electrical outputs. An open-circuit output voltage of ~40 V and short-circuit current density of ~63.6 mA m-2 with power density 0.62 W m-2 was easily obtained from the FTENG. The harvested mechanical energy is used for lighting ~100 light emitting diodes and to operate seven segment display enabling prospects for carbon-emission free environment friendly source for powering portable electronic devices. We have shown the capability of using the FTENG as self-powered weight and pressure sensors. Additionally, flexible design of the FTENG extends its application scope for self-powered tactile sensing in electronic skin for robotic application. The FTENG is simply designed, cost-effective, scalable and high-throughput for possible uses in flexible electronics, self-powered systems and body sensor networks.