Registered charity number: 207890 Showcasing research of Andrei et al. from the Laboratory of Prof. Dr Klaus Rademann, at the Humboldt-Universität zu Berlin, Germany Title: Adjusting the thermoelectric properties of copper(I) oxide–graphite–polymer pastes and the applications of such flexible composites This work presents a proof of principle study on thermoelectric pastes, which represent an environmentally friendly alternative to commonly used Bi 2 Te 3 and PbTe. Our Cu 2 O–graphite–polymer composites possess highly tunable properties, depending on the molar ratio of the added components and the percolation effect. Their applicability is revealed as flexible temperature sensors. Further material developments can result in even higher performances, allowing the production of flexible thermoelectric generators, which can directly recover electricity from temperature differences. www.rsc.org/pccp As featured in: See Klaus Rademann et al., Phys. Chem. Chem. Phys., 2016, 18, 10700.