From Batteries to Robotics: Artificial muscles with thin films on Solid composite electrolyte

Modern day robotics depend heavily on several different kinds of actuators. Contrary to conventional actuators for rigid systems (like motors, gearboxes), soft actuators or “artificial muscles” are well suited to provide high degree to freedom, adaptability, and fast response time. These soft actuators form the basis of the recent demand to biomimetic soft robots or humanoid robots. Electrochemical actuators are well suited in this regard, where appropriate materials show large deformation/strain for applied bias. For successful implementation in soft robotics, electrochemical actuators should be capable of demonstrating large, induced strain (> 1%) with low power consumption (< 1 V) coupled with fast response times and non-volatiles actuation (maintaining the deformation even after the potential bias has been removed). 

In a typical construction, electroactive actuators consist of a polymer electrolyte sandwiched between two homologous electrodes, which actuate due to migration of ions upon applied electric field. Hence, both the electrode as well as the electrolyte are important components for achieving good actuation performance. The electrolyte should have well connected ionic domains that facilitate easy ion migration while at the same time should also possess excellent mechanical properties to sustain the induced deformation. On the electrode front, materials that have high strain, high ion diffusivity, high modulus and resistance to plastic deformation are well suited for the task. Many ions insertion or intercalation type electrodes (For e.g., Si, Sn etc.), typical to Li ion battery electrode materials, have extremely high actuation-energy density and force owing to their large crystallographic strain (upon ion insertion/de-insertion) and hence might be good candidates for utilization in electroactive actuators as well. 

At imec, we have developed a solid electrolyte composite (SCE) with extremely high ionic conductivity at room temperature and with the possibility to tune its mechanical properties. In this project, you will work towards combining SCE with thin films of various electrode materials to understand their actuating behavior and cast them in robust cell designs to harness the intrinsic actuation ability of metals/alloy thin films|SCE system. For this purpose, you will have support from the thin film group for fabrication of appropriate electrodes and from the battery group at imec for synthesis and study of SCE and cell designs. You will be working in a team together with other PhD students, researchers, and engineers, while collaborating with several different universities, research institutes, and companies