Microrobotics research at EPFL and ETH Zurich means that in the future, we may be able to ingest tiny robots which deliver drugs directly to diseased tissue.
The team of scientists is led by Selman Sakar at EPFL and Bradley Nelson at ETH Zurich. The microrobotics research into highly flexible, biocompatible microrobots was inspired by bacteria.
Nelson added: “Nature has evolved a multitude of microorganisms that change shape as their environmental conditions change. This basic principle inspired our microrobot design. The key challenge for us was to develop the physics that describe the types of changes we were interested in, and then to integrate this with new fabrication technologies.”
The challenge of creating a microrobot
Microrobots are able to swim through fluids, modify their shape when necessary, and pass through narrow blood vessels without comprising on speed or manoeuvrability. The devices are made of hydrogel nanocomposites containing magnetic nanoparticles. This allows them to be controlled via an electromagnetic field.
There are many challenges associated with fabricating miniaturised robots. The scientists addressed this by using an origami-based folding method.
The novel strategy for movement employs embodied intelligence, which is an alternative to the classical computation paradigm which is performed by embedded electronic systems.
Sakar explained: “Our robots have a special composition and structure that allow them to adapt to the characteristics of the fluid they are moving through. For instance, if they encounter a change in viscosity or osmotic concentration, they modify their shape to maintain their speed and manoeuvrability without losing control of the direction of motion.”
Left to their own devices
The deformations can be programmed in advance to maximise the performance of the robots without using actuators or sensors which are cumbersome. The robots will automatically morph into the most efficient shape, either by being controlled using the electromagnetic field or left to navigate through cavities on their own by utilising the flow of fluid.