A bizarre'magnetic tentacle robot' that can pass into the narrow tubes of the lungs to take tissue samples could help save lives, a new study shows. Experts at the University of Leeds have created the device, which consists of external magnets and a'tentacle' – a thin polymer tube containing metallic particles. The so-called'tentacle' is highly flexible and measures just 0.07 of an inch (2 mm) in diameter, about twice the size of the tip of a ballpoint pen. Like something from a horror film, the tentacle would slowly enter the mouth or nose of a patient while they are under general anaesthetic. Guided by the external magnets, it could reach some of the smallest bronchial tubes in the lungs – and could be used to take tissue samples or deliver cancer therapy.