A new paper brings us one step closer to creating swarms of tiny, mobile robots.

Science fiction has long foretold of sprawling masses of tiny robots performing tasks from manufacturing and medicine to combat — with the most extreme example being the Grey Goo. We’re nowhere near that point, yet, but we’re making progress.

A new paper describes the development of a novel class of actuators (devices that can generate motion) that is comparable with current electronics. These actuators are tiny and bend when stimulated with a laser, making them ideal to power extremely small robots. A lack of proper means of movement has been a severe limitation on our efforts to design very small robots so far, the team explains.

Finding their legs

“What this work shows is proof of concept: we can integrate electronics on a [tiny] robot. The next question is what electronics should you build. How can we make them programmable? What can they sense? How do we incorporate feedback or on-board timing?” lead author Marc Miskin, assistant professor of electrical and systems engineering at the University of Pennsylvania, told me in an email.

“The good news is semiconductor electronics gives us a lot of developed technology for free. We’re working now to put those pieces together to build our next generation of microscopic robots.

Actuators are the rough equivalent of engines. Although they rarely use the same principles, they’re both meant to do physical work (a motion that can be used to perform a certain task). The lack of an adequate actuator, both in regards to size and compatibility with our current electronics, has hampered advances into teeny-tiny robots.

Marc and his team hope to finally offer a solution to this problem. The actuators they developed are small enough to power the legs of robots under 0.1 mm in size (that’s about the size of a strand of human hair). The devices are compatible with silicon-based circuitry, so no special adaptations are needed to work with them in most settings.

These actuators bend in response to a laser pulse to create a walking motion; power, in this case, was supplied by onboard photovoltaics (solar panels). As for the sizes involved here: the team reports that they can fit over one million of their robots on a 4-inch wafer of silicon.

Given that the proof-of-concept robots are surprisingly robust, very resistant to acidity, and small enough to go through a hypodermic (syringe) needle, one particularly exciting possibility is to use them for medical applications or simple biomonitoring in human and animal patients — just like in the movies. I’ve asked Marc what other potential applications they’re excited for, and the possibilities do indeed seem endless:

“We’re thinking about applications in manufacturing (can you use them to form or shape materials at the microscale?), repairing materials (can you fix defects to increase material lifespan?), and using them as mobile sensors (can you send robots into say cracks in a rock or deep in a chemical reactor to make measurements and bring data back).”

However, he’s under no illusions that this will be an easy journey. “These are of course long term goals: right now all our robots can do is walk,” he notes.

Technology and know-how, however, have a way of compounding once released into ‘the wild’ of our economies. The advent of appropriate actuators might just be the nudge needed to walk us into a series of rapid improvements on nanomachines. And I, for one, couldn’t be more excited.

The paper “Electronically integrated, mass-manufactured, microscopic robots” has been published in the journal Nature.