Researchers use organic semiconductor nanotubes to create new electrochemical actuators that have potential in numerous applications.
Actuators are a key component for robotic bioelectronic and biomedical devices. Researchers across the globe have been trying to implement actuators with significant movement and fast response time. These properties are critical for electrochemical actuator devices that operate in liquid because the drag force of a liquid restricts an actuator’s motion and limits the ion transportation and accumulation in electrode materials and structures.
Researchers from University of Houston have developed an electrochemical actuator that uses specialized organic semiconductor nanotubes (OSNTs). The researchers refined methods of working around those two properties.
“Electrochemical devices that transform electrical energy to mechanical energy have potential use in numerous applications, ranging from soft robotics and micropumps to autofocus microlenses and bioelectronics,” said Mohammad Reza Abidian, associate professor of biomedical engineering in the UH Cullen College of Engineering.
“Our organic semiconductor nanotube electrochemical device exhibits high actuation performance with fast ion transport and accumulation and tunable dynamics in liquid and gel-polymer electrolytes. This device demonstrates an excellent performance, including low power consumption/strain, a large deformation, fast response and excellent actuation stability,” Abidian said.
The high performance of this newly developed actuator is due to the large effective surface area of the nanotubular structure, which facilitates the ion transport and accumulation, resulting in high electroactivity and durability.
“The low power consumption/strain values for this OSNT actuator, even when it operates in liquid electrolyte, mark a profound improvement over previously reported electrochemical actuators operating in liquid and air,” Abidian said. “We evaluated long-term stability. This organic semiconductor nanotube actuator exhibited superior long-term stability compared with previously reported conjugated polymer-based actuators operating in liquid electrolyte.”
To demonstrate the wide applicability range of this actuator, researchers developed a micron-scale movable neural probe that is based on OSNT microactuators. According to the researchers, the probe can be implanted in the brain, where neural signal recordings that are adversely affected, by either damaged tissue or displacement of neurons, may be enhanced by adjusting the position of the movable microcantilevers.
“Considering the achievements so far, we anticipate these new OSNT-based electrochemical devices will help advance the next generation of soft robotics, artificial muscles, bioelectronics and biomedical devices,” Abidian said.
The research has been published in the journal Advanced Functional Materials.