Biomimetic multi-stimuli responsive flexible sensors – DEFORM

Nature uses various activation mechanisms to create shape transformations (actuation) and translate functional information (sensing) of living organisms. Inspired by such natural organisms, we aimed to develop biomimetic sensors and actuators that respond simultaneously to multiple stimuli of different deformation shapes combined with electrical detection. These biomimetic devices consist in polymer MEMS made of functional organic constitutive elements such as chemical responsive materials and electroactive polymers (EAPs). Thanks to their particular properties (low cost, flexibility, biocompatibility, responsiveness to external stimuli), polymer and composite material-based MEMS have the potential to be a powerful alternative to silicon-based MEMS devices for emerging applications such as biomedicine, soft robotics and wearable electronics.

Initially, electrically actuated soft micro-cantilever based on ferroelectric relaxor material, P(VDF-TrFE-CTFE) will be fabricated and characterized. Secondly, complex 3-dimensional (3D) deformations of organic MEMS will be induced in a control manner through the tuning of the material rigidity as well as the integration of stiffeners with high Young’s modulus materials or inversely partial etching. Subsequently, chemical responsive materials sensitive to organic volatile compounds (VOCs) will be implemented on those soft actuators as sensitive layer. Inspired from plants’ architecture and using mechanical modeling, micro and nano-pattern of functional materials with specific features of controlled size and shape to create targeted deformations, such as twisting will be achieved through printing technologies. The electromechanical transduction will be realized using chemiresistive or capacitive approaches. Although growing interest is devoted to biomimetic soft actuators that have contributed to substantial progress in the field, to our knowledge, at this point, no biomimetic soft sensor with integrated electronic readout has been realized, which is a prerequisite for future industrial applications. In addition, we also aim to develop functional material that respond to a whole set of stimuli by (i) modification of the material itself (functionalization, porosity) and (ii) fabrication of composites that introduce an additional functionality (i.e. throughout the conception of a conductive thermoelectric materials). Progress in developing multi stimulus-active materials would represent a major breakthrough in the field and favor broadening the fields of applications of polymer-based transducers.

In brief, the DEFORM project aims at developing an emerging form of technology based on bio-inspired MEMS sensors with potential advantages such as low cost, realization of a large number of structures/shapes with the capability of 3-dimensional (3D) actuation with integrated electrical transduction made by combining functional organic constitutive elements. We strongly believe that the results from DEFORM will greatly contribute to the development of the field of biomimetic soft MEMS. In fact, biomimetic devices are driven by the strong need for reliable 3D microstructures able to sense multiple stimuli ready for future industrial and economic development for wearable electronics and soft robotics markets. In agreement with the scientific coherence and background of the laboratory of the coordinator, elaboration of organic sensors and actuators based on EAPs and chemical responsive materials micromachining is a new, original and breakdown approach that is being developed. The development of DEFORM will reinforce to the current synergy of the ORGANIC group at IMS, while it will permit to the coordinator to acquire leading scientific and management activities in the group.