The cooperative research of Professor Choi Eun-pyo of the CNU Robot Research Initiative (Director: Park Jong-oh) and Professor Qinchuan Li and Fan Wang of Zhejiang Sci-Tech University successfully developed a biomaterial-based artificial muscle that has the world's highest strain rate at a very low voltage.
The result of this research is a core technology in the field of soft robotics and received an excellent evaluation as a source technology that can solve problems such as the high driving voltage and low reaction speed of existing biomaterial-based artificial muscle technology.
Soft robotics is expected to overcome the shortcomings of traditional metal robotics in fields such as medicine, rehabilitation, and wearable robotics. The shape of soft robotics can be changed flexibly and freely, imitating the movement of flexible animals such as octopus, fish, or microbes.
Researchers in the field are paying attention to the development of ionic soft actuators that have characteristics of less noise and vibration, in addition to low-power consumption to drive soft robotics. Research has been conducted to develop wearable devices and medical soft robotics that can be inserted into the human body, spurring the development of so-called artificial muscles, soft actuators based on human-friendly biomaterials.
However, traditional ionic soft actuators based on biomaterials were difficult to apply to soft robotics due to their very low strain rate, poor reaction speed, and short lifespan.
That is why the new findings of the CNU co-research team are drawing attention. The joint research team developed an ionic soft actuator (artificial muscle) that has the world's best strain and reaction rate by coating a conductive polymer, polypyrrole, on a soft actuator based on bacterial cellulose, a biodegradable and biocompatible material.
The research team coated polypyrrole nanoparticles for high conductivity and additionally coated them with PEDOT:PSS, a soft and flexible conductive polymer, and used it as a flexible electrode. The result was a high strain (0.93%) at a low driving voltage (0.5V) with a fast reaction rate (4 seconds), setting the highest record among existing biomaterial-based ionic soft actuators. In addition, after driving for 5 hours at 0.5V and 0.1Hz cycles, it remained stable with almost no performance change.
This research was carried out with support from the Common Infrastructure Technology Development Center for the Micro Medical Robot Practical Technology Development Project governed by the Ministry of Health and Welfare and the National Natural Science Foundation of China. It was selected as the cover paper of the renowned international academic journal Advanced Functional Materials (Impact Factor: 16.836), Issue 31, 2021 (March 24).
