Scientists from Nanyang Technological University (NTU) in Singapore have developed paper-thin biodegradable zinc batteries that could one day become an environmentally sustainable option for powering flexible and wearable electronic systems.

The NTU Singapore-developed batteries consist of electrodes screen-printed on to both sides of a piece of cellulose paper that has been reinforced with hydrogel.

Once the battery has been expended, it can be buried in soil, where it breaks down completely within a month.

In a proof-of-concept experiment described in scientific journal Advanced Science, the NTU team demonstrated how a 4cm x 4cm square of printed paper battery could power a small electric fan for at least 45 minutes. Bending or twisting the battery did not interrupt the power supply.

In another experiment using a 4cm x 4cm battery to power an LED, the scientists showed that despite cutting away parts of the paper battery, the LED remained lit, indicating that cutting does not affect the functionality of the battery.

This points to a cheaper and simpler way of manufacturing batteries – by making a large that can be cut to desired shapes and sizes without loss of efficiency. It could potentially help with the electronic waste problem as well, given that the printed paper battery is non-toxic.

The scientists think their printed battery could be integrated into flexible electronics such as foldable smart phones that are already on the market, or biomedical sensors for health monitoring.

www.ntu.edu.sg