A soft robot shaped like a Möbius strip can move when activated by light, and could be used to transport medicine and collect samples inside the body.
Zi Liang Wu at Zhejiang University in China and his colleagues created their strips from thin sheets of hydrogels, materials made from long chain-like polymer molecules linked together by water molecules. They made the strips into unusual shapes, such as a Möbius strip – a one-sided surface that results from a band with a twist in it – or a similar curved surface called a Seifert ribbon.
