In the American action movie “Pacific Rim”, giant robots called “Jaegers” fight unknown monsters to save humanity. These robots are equipped with artificial muscles that mimic real living bodies and defeat monsters with power and speed. Recently, research is underway to equip real robots with artificial muscles like those shown in the film. However, the powerful force and high speed of artificial muscles cannot be actualized because the mechanical strength (force) and conductivity (speed) of the polymer electrolyte – the key materials driving the actuator – have contradictory characteristics.
A POSTECH research team led by Prof. Moon Jeong Park, Prof. Chang Yun Son and Research Prof. Rui-Yang Wang from the Department of Chemistry developed a new concept of polymer electrolyte with different functional groups located at a distance of 2Å . This polymer electrolyte is capable of both ionic interactions and hydrogen bonds, thus opening up the possibility of resolving these contradictions. The results of this study were recently published in the international academic journal Advanced materials.
Artificial muscles are used to make the robots move their limbs naturally like humans can. To train these artificial muscles, an actuator that exhibits mechanical transformation under low voltage conditions is needed. However, due to the nature of the polymer electrolyte used in the actuator, force and speed cannot be achieved simultaneously as increased muscle strength slows switching speed and increasing speed reduces strength.
To overcome the limitations presented so far, research has introduced the innovative concept of bifunctional polymer. By forming a one-dimensional ion channel several nanometers wide inside the polymer matrix, which is hard as glass, a superionic polymer electrolyte with both high ionic conductivity and high mechanical strength was obtained.
The results of this study have the potential to create innovations in soft robotics and wearable technology as they can be applied to the development of an unprecedented artificial muscle that connects a wearable battery (1.5 V), produces rapid switching of several milliseconds (thousandths of a second), and great force. Moreover, these results should be applied in next-generation semiconductor electrochemical devices and highly stable lithium metal batteries.
This study was conducted with support from the Samsung Science and Technology Foundation.
