Flexible thermoelectric generators that are capable of producing electricity out of a temperature difference could have many applications in consumer and medical electronics. However, conventional thermoelectric materials are rigid and brittle and don't lend themselves to be used with flexible devices. Researchers have now demonstrated a flexible paper-based devices can be easily stacked or efficiently folded and cut through origami and kirigami techniques so that it is possible to achieve higher power densities. This allows for enough electricity to be generated to supply low-power systems, especially in applications where flexibility is advantageous, such as robotics, cybernetics, wearable devices or bio-integrated systems.