All living things are built with 20 amino acids in myriad combinations, so why not machines and robots? This is the inspiration for a novel fabrication method from MIT which employs a handful of multi-use parts to create all manner of tiny machines. Machines that eventually, may even be able to build themselves.

Yet again, technology draws inspiration from nature. MIT Professor Neil Gershenfeld's musings on amino acids led him to come up with the concept of "digital materials," a discrete, limited set of parts that can be assembled like a kind of tiny Erector-set, into a potentially limitless variety of tiny machines and robots.

Gershenfeld's paper on the method (co-authored by MIT graduate student, Will Langford) was presented at the International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS) in Helsinki, Finland this week. At the conference, the team demonstrated the assembly and deployment of a tiny walking motor, and one which was able to turn the gears of a machine, using just five different part designs.

A single-layer walking motor, is made using the assembler with only five part designs Will Langford and Neil Gershenfeld/MIT

These five-part designs (which include rigid and flexible components, a coil, and magnetics) are at the millimeter-scale, and connect to each other via a standard connector in a number of configurations. The parts can be assembled into a robot for a specific task – which can be expanded upon with more components from the set – or they can easily be disassembled and repurposed to create a new machine for a different task. On a larger scale, this efficient approach could negate the costly process of designing and building new robots from scratch with bespoke parts for each application.

The challenge wasn't just to figure out what these multipurpose components might look like and do. The real challenge – and one the team feels it's met – is how they'd be made and assembled in the first place, with Gershenfeld stating the ultimate goal is to make an assembler that can assemble a copy of itself out of the parts that it's assembling.

To this end, Langford built a fabrication device that is akin to a mashup of a 3-D printer and the sort of pick-and-place machine you'd normally see creating electronic circuit boards. The device is fed a digital design and it sets to work creating machines and robots from the componentry. This automation relies heavily on the simplicity and regularity of the design of each of the discrete components within the set – a key factor in the interoperability, reliability and scaleability of the designs.

This walking microrobot was built by the MIT team from a set of just five basic parts, including a coil, a magnet, and stiff and flexible structural pieces Will Langford/MIT

Speaking of scale, the possible applications for this Lego-like assembly system aren't limited to tiny robots, as each component can be down- or upscaled to suit the end purpose. To demonstrate this, the team has made nanorobots from nanometer-sized parts, and megarobots from meter-sized parts.

The work continues and as more unique parts are designed – perhaps up to the magic 20 as it is with Gershenfeld's amino acids inspiration – the possibilities for this methodology will no doubt expand exponentially.

The research was presented this week at MARSS 2019 Helsinki. A video of various assembled micro-machines using the five discrete part designs can be seen below.

Source: MIT News