It may sound like the plot of'Fantastic Voyage', but miniature robots that can travel around the human body and dispense medicines could soon be a reality. Researchers at Stanford University have developed a'millirobot' that can roll, flip, spin, and even swim to enter narrow spaces. The fingertip-sized machine is inspired by the Japanese paper-folding art of origami and can be controlled using magnets – carrying drug treatments directly to a tumour, blood clot, infection or pain point. The millirobot could revolutionise medicine, according to the researchers, replacing pills or intravenous injections that can cause unwanted side effects. In the 1966 sci-fi classic Fantastic Voyage, a submarine and its crew are shrunk and injected into a dying patient, where they venture through his veins into his brain and destroy a blockage using laser guns.

Cancer drugs usually take a scattergun approach. Chemotherapies inevitably hit healthy bystander cells while blasting tumours, sparking a slew of side effects. It is also a big ask for an anticancer drug to find and destroy an entire tumour -- some are difficult to reach, or hard to penetrate once located. A long-dreamed-of alternative is to inject a battalion of tiny robots into a person with cancer. These miniature machines could navigate directly to a tumour and smartly deploy a therapeutic payload right where it is needed. "It is very difficult for drugs to penetrate through biological barriers, such as the blood–brain barrier or mucus of the gut, but a microrobot can do that," says Wei Gao, a medical engineer at the California Institute of Technology in Pasadena.

At the beginning of the new millennia, wireless capsule endoscopy was introduced as a minimally invasive method of inspecting the digestive tract. The possibility of collecting images deep inside the human body just by swallowing a "pill" revolutionized the field of gastrointestinal endoscopy and sparked a brand-new field of research in robotics: medical capsule robots. These are self-contained robots that leverage extreme miniaturization to access and operate in environments that are out of reach for larger devices. In medicine, capsule robots can enter the human body through natural orifices or small incisions, and detect and cure life-threatening diseases in a non-invasive manner. This talk provides a perspective on how this field has evolved in the last ten years.

Tiny'Living robots' named Xenobots have been created from frog embryos and they could be used to destroy cancer cells or remove microplastics from the oceans. They were developed by researchers from Vermont University and Tufts University who adapted stem cells taken from the embryo of the African frog Xenopus Laevis. The bots are just a 25th of an inch wide (1mm) and can be programmed to perform a range of tasks including delivering medicine directly to a point in the body. Researchers say the new'artificial cells' can be shaped in any way necessary for the task at hand and are'indestructible' and able to self repair. 'They're neither a traditional robot nor a known species of animal.