Operation of a low-temperature differential heat engine for power generation via hybrid nanogenerators

•Nanogenerators were fabricated and operated using a Low Temperature Differential (LTD) heat engine.•Contact sliding mode and vertical contact-separation mode were applied in 4 schemes.•Two nanogenerators were operated simultaneously to exploit low-grade thermal energy.•Nanogenerators along with an electromagnetic generator was also explored for power enhancement.•Readily charged a capacitor to drive low power electronic appliances such as LEDs. This work aims for the exploitation of low-grade thermal energy (