World’s first minuscule molecule-building robot paves way for molecular factories

For years science fiction writers have described a future where tiny robots are able to move about in the human body, administering treatments on a molecular level. Now that future is on the edge of reality with the development of the world’s first ‘molecular robot’: a micrometre-sized bot capable of building molecules.

Each robot is a millionth of a millimetre in size and is made up of just 150 hydrogen, nitrogen, oxygen and carbon atoms: in order to match the size of a grain of salt, you would need to pile a billion billion of the robots on top of each other.

Each can be programmed chemically to perform basic tasks such as constructing molecules out of component atoms, meaning that in the future they could be used to aid medical treatments, or work in tiny molecular factories creating molecules for a host of industries.

“It is similar to the way robots are used on a car assembly line. Those robots pick up a panel and position it so that it can be riveted in the correct way to build the bodywork of a car,” said research leader Professor David Leigh, from the University of Manchester’s School of Chemistry. “So, just like the robot in the factory, our molecular version can be programmed to position and rivet components in different ways to build different products, just on a much smaller scale at a molecular level.”

Image courtesy of Stuart Jantzen, www.biocinematics.com

While regular sized robots are programmed using commands imputed through a computer, these robots are instructed using chemicals.

“The robots are assembled and operated using chemistry. This is the science of how atoms and molecules react with each other and how larger molecules are constructed from smaller ones,” explained Leigh.

“It is the same sort of process scientists use to make medicines and plastics from simple chemical building blocks. Then, once the nano-robots have been constructed, they are operated by scientists by adding chemical inputs which tell the robots what to do and when, just like a computer program.”

The robots could be used to form microsopic version of factories. Image courtesy of Nataliya Hora / Shutterstock

While the research is at an early stage, the robots could in the future be used to work in tiny factories, which could – for example – reduce demand for materials, speed up drug discovery and dramatically cut power requirements.

“Molecular robotics represents the ultimate in the miniaturisation of machinery. Our aim is to design and make the smallest machines possible,” said Leigh.

“This is just the start but we anticipate that within 10 to 20 years molecular robots will begin to be used to build molecules and materials on assembly lines in molecular factories.”

The research will be published in Nature on Thursday.

Gecko-inspired robotic gripper to clear up space junk

Researchers have developed a pioneering robotic gripper that uses gecko-inspired sticky pads to clear up space debris.

Developed at Stanford University and NASA’s Jet Propulsion Laboratory (JPL), and detailed today in the journal Science Robotics, the gripper has been tested both on the ground and on the International Space Station, demonstrating that it can successfully operate in zero-gravity environments.

With around 500,000 pieces of man-made debris littering orbit, there is a growing need to successfully clear much of it so that humanity can safely increase its operations in low-Earth orbit. Each piece of space junk is whizzing around at up to 17,500 miles per hour, meaning a collision with a satellite, spacecraft or even astronaut would be extremely expensive and potentially very dangerous.

However, many conventional junk removal methods don’t work particularly well. Suction cups rely on creating a difference in air pressure, meaning they don’t work in a vacuum; magnets only work on a limited number of materials and debris harpoons risk missing and knocking the objects off in unpredictable directions.

Sticky solutions, then are preferred, however most tape-like solutions fail because the chemicals they rely on to make them sticky can’t cope with the massive temperature changes objects in space are subjected to. Which is where the gecko-inspired gripper comes in.

The robotic gripper being tested on NASA’s low-gravity aircraft the Weightless Wonder. Image, video  and featured image courtesy of Jiang et al., Sci. Robot. 2, eaan4545 (2017)

“What we’ve developed is a gripper that uses gecko-inspired adhesives,” said study senior author Mark Cutkosky, professor of mechanical engineering at Stanford. “It’s an outgrowth of work we started about 10 years ago on climbing robots that used adhesives inspired by how geckos stick to walls.”

Geckos are able to scale vertical surfaces because they have microscopic flaps that create weak intermolecular forces between the feet and the wall’s surface, allowing them to grip on. The researchers have simply replicated these flaps, albeit on a larger scale; while each flap on a gecko’s foot is around 200 nanometers long, on the robotic gripper it is only 40 micrometers across.

However, it works in the same way, allowing an object to be gripped in a zero-g environment without needing to apply force.

“If I came in and tried to push a pressure-sensitive adhesive onto a floating object, it would drift away,” said study co-author Dr Elliot Hawkes, a visiting assistant professor from the University of California, Santa Barbara. “Instead, I can touch the adhesive pads very gently to a floating object, squeeze the pads toward each other so that they’re locked and then I’m able to move the object around.”

A close-up of the prototype gripper. Image courtesy of Kurt Hickman/Stanford News Service

The gripper has already undergone extensive testing, including in JPL’s Robodome, which has a floor like a giant air hockey table that is designed to simulate a 2D zero-G environment.

“We had one robot chase the other, catch it and then pull it back toward where we wanted it to go,” said Hawkes. “I think that was definitely an eye-opener, to see how a relatively small patch of our adhesive could pull around a 300kg robot.”

Now it has been tested on the International Space Station, the next step is to test a version outside the space station, in the radiation-filled reality of space. Cutkosky also plans to commercialise the gecko-inspired adhesive here on Earth.