A small robot that can shape-shift and produce heat could incinerate cancer cells or stop bleeding from inside the body. It could also be used to ferry drugs directly to tumours or hard-to-reach places like arteries.

Tiny robots with soft bodies have shown promise for delivering drugs without causing damage – but adding hard elements could make them more useful.

at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany, and his colleagues designed the centimetre-sized robot to have overlapping aluminium plates inspired by pangolins, the only mammal with scales. They layered rectangular “scales” over softer, magnetic material, which let the robot change its shape.

To make it move, curl up, stretch out or get warm, the researchers directed magnetic fields at the robot’s metal parts. Changing the frequency of these fields could also make the scales heat up, allowing the robot to blast its surroundings with heat. They found that the robot’s body could warm up to more than 70°C.

The researchers also used the robot’s heat to deliver cargo within a model of a stomach. They stuck a piece of rubbery material to the robot to imitate capsules of medicine. The adhesive they used dissolved when the robot warmed up, depositing the cargo. This could allow for targeted drug delivery within the body.

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Soon and his colleagues also tested the robot’s ability to stop bleeding from wounds using the stomach of a dead pig. They simulated bleeding by pumping blood with a syringe through a small cut. Then, the robot stretched out and laid over the spot, heating it up to make the blood clot.

at the University of Utah says the robot could also be used to kill tumour cells in a targeted way instead of exposing large amounts of tissue to radiation or chemicals. “You could raise the temperature of the robot above an unsafe level [for normal cells] and hold it in place for a few minutes, and that can kill [cancer] cells. The human body is very sensitive to temperature,” he says.

A collaboration between Neon Dance and Bristol Robotics Laboratory is due to open at The Place in London on 14 October. Prehension Blooms is a dance piece starring telepresence robots based on sand-dwelling organisms, which interact with human performers.

A gearbox driven by an external magnetic field can power tiny but powerful robots that crawl like a caterpillar or jump almost 40 times their own height, despite having no batteries or motors on board. The technology could lead to medical robots that can travel through the human body, taking samples or delivering drugs.

Soft robots – which have no batteries, motors or electronics and are powered and controlled remotely by light or magnets – are a popular field of research because their simplicity enables them to be highly miniaturised. But they may be lacking in power when the task requires puncturing skin or opening collapsed cavities.

Now, at the Max Planck Institute for Intelligent Systems in Germany and his colleagues have created a gearbox that measures around 3 millimetres across and is equipped with cogs as small as 270 micrometres in diameter.

The gears are cast from epoxy resin impregnated with aluminium. A magnet fitted to the input shaft is driven by an external, spinning magnetic field that amplifies the torque – or rotational force – by up to 342 times.

Read more: Robot made of sticky tape and metal powder could crawl on your organs

These gearboxes – which contain seven gears to amplify the input – can be fitted into various modular robots to accomplish a range of tasks: one crawls like a caterpillar at 0.68 millimetres per second, another stores energy in elastic legs and jumps 119 millimetres, while others clamp on to solid objects which they puncture with a needle.

When put to the test, a winch-like robot equipped with a gearbox was able to lift 103 grams.

Hong says the technology can allow the creation of more powerful and complex soft robots, although they will need solid gearbox machinery at their core.

“In the future we may use the robot in confined spaces, like the human body, or in granular media [such as sand] like [how] an earthworm [moves],” he says.

“Compared to other magnetic robots, ours just requires a very small magnetic field, so we can put our control system far away from the robot, because the gearbox amplifies the magnetic force to function. So maybe this robot can obtain a larger working distance [than existing soft robots].”

A robot with a pair of grippers on its arms can untangle long, knotted cables. The technology could be used to fit electrical cables in aircraft or offer household assistance to older people, but at the moment, the robot struggles if it drops something, because it can’t bend down to pick it up again.

at the University of California, Berkeley, says his team’s work on the robot was inspired by untidy cables getting in the way in the laboratory, which made him think about how a robot would have to work to keep them tucked away. The problem requires dextrous mechanical arms, but also an understanding of knot theory, he says.

“There’s a beautiful mathematical body of theory out there on knots, and it’s very abstract. It generally abstracts the problem into graphs and graphical structures,” says Goldberg. “We applied certain aspects of that. Cables are difficult to perceive, even with the best of cameras and techniques, and they’re also difficult to manipulate because of their flexibility and their small size and their tendency to spring out and do things that are very unpredictable.”

The robot is mounted to a table on which a knotted cable also rests. It is fitted with a camera that can observe visible light and measure depth. The images it records are fed into an artificial intelligence, which interprets them and creates an accurate map of the orientation and configuration of the cable along its length.

There are several strategies that the robot’s control algorithm uses to untie knots, and it applies them iteratively as needed until the whole cable is straightened out. Initially, the robot uses its camera to scan the cable and form a map of the structure of any knots. If this is ambiguous, it can gently pull at the cable on either side of the knot to remove loose loops of cable and leave only knots remaining, or shake the cable to remove superfluous loops, and then scan again.

The robot can then grasp the cable at two different points and pull it apart, with both of its 3D-printed grippers able to either firmly seize the cable or hold it loosely to allow movement, in order to slowly unweave the knot. The final task is to slowly pass along the cable from one end to the other and check that all knots have been removed.

In experiments with a braided 2.7-metre micro-USB to USB cable, the robot had a success rate of 67 per cent on single, simple knots and 50 per cent on more complex tangles. Some of the failures included the cable falling off the table, from where the robot was unable to retrieve it.

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Robots can now be covered in living skin grown from real human cells to make them look more like us.

As robots increasingly take on roles as nurses, care workers, teachers and other jobs that involve close personal contact, it is important to make them look more human so we feel comfortable interacting with them, says at the University of Tokyo in Japan.

At the moment, robots are sometimes coated in silicone rubber to give them a fleshy appearance, but the rubber lacks the texture of human skin, he says.

To make more realistic-looking skin, Takeuchi and his colleagues bathed a plastic robot finger in a soup of collagen and human skin cells called fibroblasts for three days. The collagen and fibroblasts adhered to the finger and formed a layer similar to the dermis, which is the second-from-top layer of human skin.

Next, they gently poured other human skin cells called keratinocytes onto the finger to recreate the upper layer of human skin, called the epidermis.

The resulting 1.5-millimetre-thick skin was able to stretch and contract as the finger bent backwards and forwards. As it did this, it wrinkled like normal skin, says Takeuchi. “It is much more realistic than silicone.”

The robot skin could also be healed when it was cut by grafting a collagen sheet onto the wound.

However, the skin began to dry out after a while since it didn’t have blood vessels to replenish it with moisture.

In the future, it may be possible to incorporate artificial blood vessels into the skin to keep it hydrated, as well as sweat glands and hair follicles to make it more realistic, says Takeuchi.

It should also be possible to make different skin colours by adding melanocytes, he says.

The researchers now plan to try coating a whole robot in the living skin. “But since this research field has the potential to build a new relationship between humans and robots, we need to carefully consider the risks and benefits of making it too realistic,” says Takeuchi.