Researchers, drawing inspiration from bacteria, have designed smart, bio-compatible microrobots that are highly flexible. Because these devices are able to swim through fluids and modify their shape when needed, they can pass through narrow blood vessels and intricate systems without compromising on speed or maneuverability.

Robots can change shape depending on their surroundings. (© 2019 EPFL/ETHZ)

They are made of hydrogel nanocomposites that contain magnetic nanoparticles, allowing them to be controlled via an electromagnetic field. The researchers “programmed” the robot’s shape so it can easily travel through fluids that are dense, viscous, or moving at rapid speeds.

Fabricating miniaturized robots presents a host of challenges that were addressed using an origami-based folding method. The novel locomotion strategy employs embodied intelligence that is an alternative to the classical computation paradigm performed by embedded electronic systems. The robots have a special composition and structure that allow them to adapt to the characteristics of the fluid through which they are moving; for example, if they encounter a change in viscosity or osmotic concentration, they modify their shape to maintain their speed and maneuverability without losing control of the direction of motion.

These deformations can be programmed in advance to maximize performance without the use of cumbersome sensors or actuators. The robots can be controlled using either an electromagnetic field or left to navigate on their own through cavities by utilizing fluid flow. Either way, they will automatically morph into the most efficient shape.

For more information, contact Dr. Mahmut Selman Sakar, Assistant Professor, Institute of Mechanical Engineering at EPFL at This email address is being protected from spambots. You need JavaScript enabled to view it.; +41 21 6931095.