Scientists have layered gold on top of the skin of an onion to create an artificial muscle.

The initial goal of the researchers from National Taiwan University was to develop an engineered microstructure in artificial muscles for increasing the amount the muscle can bend or stretch when triggered.

“One day, we found that the onion’s cell structure and its dimensions were similar to what we had been making.” said lead author Wen-Pin Shih.

Unlike previous designs the new artificial muscle can either expand or contract to bend in different directions depending on the driving voltage applied. 

The findings are published in Applied Physics Letters.