Minuscule gears that are thinner than a human hair and powered by light could be used to study human cells or power tiny, complex robots.
Gear systems often struggle to work at a size below a tenth of a millimetre, about the thickness of an average piece of paper, because it is difficult to miniaturise the power systems that drive them. Some simple systems, such as rotors built from DNA, can be built at nanoscales, but these are bespoke and can鈥檛 be used for more complex machines.
Now, at the University of Gothenburg in Sweden and his colleagues have developed micrometre-scale gears that can be used to build functioning micromachines. 鈥淲e鈥檙e providing a platform which can fabricate any kind of machine you can imagine for these kinds of scales,鈥� says Wang.
Advertisement
The gears are carved out of silicon by a beam of electrons using the same lithography techniques behind the creation of computer chips. This means they can be fabricated with high precision and fit together snugly. 鈥淵ou can have gears of maybe 5 microns that are able to move at the same time and don鈥檛 get stuck,鈥� says Wang.
Once fitted together, they can be driven by a single gear with an attached metasurface, a 2D surface that is engineered to move in response to light.
Wang and his team used these gears to construct a micromachine that can translate motion through up to six interlinked gears at the same time. They also created a geared mechanism for controlling the movement of a microscopic gold mirror, which could be used in an optical device.
, also at the University of Gothenburg, says the team is additionally exploring how to build machines on the scale of human cells to study how mechanical forces influence the growth of tissues.
鈥淚t鈥檚 fascinating physics, interesting technology and also very versatile, because all propulsion occurs on the [meta] surface,鈥� says at Sapienza University of Rome in Italy. 鈥淎s long as you can print this surface on a part of your micro device, you can make it [activated by light].鈥�
arXiv
