Edwin Jager and his team at Linköping University have found a new way of controlling micromotors, making very small vehicles move with bubbles as propulsion. They can now switch the motors on and off electrically, something the researcher had no prior method of doing.
Researchers at the Division Sensor and Actuator Systems at Linköping University have developed a new method to electronically control micromotors, paving the way for steerable microvehicles used in applications like targeted drug delivery and microscale sensing.
The team, lead by professor Edwin Jager, introduced micromotors powered by bubble propulsion that can be turned on or off via electrical signals, something not previously possible. The key lies in a smart use of polypyrrole, an electroactive polymer, in combination with catalytic platinum.
“We devised adding an electroactive polymer layer on the platinum surface of the motor that can electrically control the diffusion of H2O2, that is we can electrically control the fuel supply to the motor thus we are able to electrically turning on or off the catalytic motor“, says Edwin Jager.
The micromotors are designed to propel forward, using oxygen bubbles that are generated when hydrogen peroxide converts to oxygen on a platinum surface. But without the polymer layer added in this project the reaction is instant the second the two components come in contact.
“What we have done is to be able to electrically control the diffusion of oxygen through the electroactive polymer layer. We then apply a negative potential to the polymer, enabling the two components to react and oxygen bubbles are generated”, says Edwin Jager.
When the bubbles are created, the motor propels, and to shut it off the process is revered by applying a positive potential to the polymer.
What might be the future use of these types of motors?
“They could be used to control of micro-and nanorobots and micromotors that can deliver cargo and/or do precise minimal-invasive therapeutical treatments inside the body. This would require another catalytic fuel source like glucose, but such glucose drive catalytic micro/nano-motors have been demonstrated. They could also be used for microvehicles with integrated sensor systems for use in environmental monitoring in aqueous environments. Or to drive micropumps.”
Read the full publication here: Advanced Robotics Research
