Terpolymer Electroactive Actuator for Mini-invasive surgery – TEAM

Mini-Invasive Surgery (MIS) has evolved with the micro-catheters and surgical endoscopic devices innovation in most medical fields. These technologies are moving towards even greater miniaturization and flexibility of the tools. Micro-actuators are not exempt from this wave of innovation since the emergence of smart materials and soft robotic. Among these smart materials, electroactive polymers have aroused a real enthusiasm for their reversible, repeatable and controllable deformation capabilities. We have therefore studied these materials and, more particularly, the Relaxor-Ferroelectric (RFE) and electrostrictive terpolymer P(VDF-TrFE-CTFE) for its biocompatibility and bending performances. Following the ANR FETA dedicated to the study of the structure and properties of this electroactive material, the TEAM consortium wishes to focus on the manufacturing of a multilayered composite material actuator based on electroactive polymers for surgical endoscopic devices. The multilayer actuator design that consists in alternating electroactive and conductive layers is proposed to reduce the electroactive polymer (EAP) layer thicknesses, and thus their corresponding driving voltage (proportional to the film thickness).
Researchers in mechanics and robotics and researchers in polymeric and composite materials from the PIMM and IMS laboratories will join forces with researchers from ARKEMA and SYROBO to promote the very promising results obtained during previous work and, thus, enable a growth in the TRL of these innovative technologies. The objectives of TEAM are as follows:
- To optimize the ink formulation and the fabrication process of an electroactive polymer-based actuator to achieve multilayer composite material throughout the understanding of the physico-chemical influences of the processing conditions of printing processes on the coating. Concretely, the effect of the following parameters namely pressure, speed, mesh type for screen-printing and the solvent and withdrawal rate for dip-coating will be investigated. The conception of multilayered EAP actuators is a challenging task that should provide valuable insights on the influence of numerous geometrical and physical parameters on the device performance
- To develop a finite element digital prototyping platform to guide the manufacturing process of this actuator through a robust digital twin that consists in Finite Elements (FE) Multiphysics simulations involving large displacements within Abaqus© software. This digital twin will be used to guide the choice of multiple parameters of the fabrication process such as the thickness, number of layers, mechanical properties of the active materials and the physical characteristics of the flexible/elastomer substrate and electrodes.
- To develop and validate an optimized manufacturing printing process of multilayered actuator onto specific location of the tubular structure to allow mechanical motion in three-dimension. To characterize the electromechanical features (mechanical displacement and generated force) of the soft multilayered continuum actuators in air and aqueous media.
-To evaluate the actuator performances for medical endoscopic integration through a numerical and an experimental bench test developed with the urologist surgeons of TENON Hospital and SYROBO.
In brief, the TEAM project aims to combine advanced materials and their manufacturing processes with mechanical and numerical analysis and control theory to develop an innovative multilayer EAP medical soft continuum actuator dedicated among others to mini-invasive surgery.