You have witnessed a variety of nano-devices that were designed for tasks including delivering medicines within the body. All of them used to move in a variety of ways. However, the latest nano-device is a four-legged nano-robot that will be able to walk up to its target. The technology was first developed by Asst. Prof. Marc Miskin from the University of Pennsylvania when he was a postdoc at Cornell University. Other professors in his team included Itai Cohen and Paul McEuen. The team also had a researcher by the name of Alejandro Cortese.
Thanks to a proprietary multistep nanofabrication method, batches of about a million of the 70-micron-long nano-robots can be manufactured in only weeks. All of them will be created using a single 4-inch silicon composite wafer. Talk about speeding up the manufacturing process and exponentially enhancing the quantity!
Each robot is comprised of an ultrathin glass rectangle that has been crowned with a silicon layer. The silicon layer features the electronic control components and two or four solar cells. The legs, four of them, are crafted using a material that is 100-atom thick. The material has a layer of platinum and another layer of titanium (although titanium can be replaced with graphene as well).
When a laser is shone on the solar cells, the electric current is applied to the front and rear legs alternatively and back and forth. This current application causes the platinum to expand whereas the titanium remains rigid thus bending the leg. Once the current is switched off, the leg straightens again. Using this technique, the nano-robots are able to walk forward. The nano-robots are so small that they can be injected into the body by making use of a hypodermic needle.
As of right now, the nano-robots can only travel inside the layer of tissue up to the width of a fingernail. Why? Because the external laser can only penetrate this width. However, Miskin is actively looking for alternate power sources that can help increase this distance. The options include ultrasound and magnetic fields. His colleagues at the University of Pennsylvania and Cornell University are also brainstorming on ‘smart’ versions of these nano-robots, trying to incorporate sensors, clocks, and self-controllers.
Miskin will be showcasing his research at the American Physical Society March Meeting that will be held in Boston.