Polymeric foams for flexible and highly sensitive low-pressure capacitive sensors

Mickaël Pruvost (1) , Wilbert Smit (2) , Cécile Monteux (3) , Philippe Poulin (4) , Annie Colin (4)

1 GRAMFC - Groupe de Recherche sur l'Analyse Multimodale de la Fonction Cérébrale - UMR INSERM_S 1105
2 CBI - Chimie-Biologie-Innovation (UMR 8231)
3 SIMM - Sciences et Ingénierie de la Matière Molle (UMR 7615)
4 CRPP - Centre de recherches Paul Pascal

Flexible low-pressure sensors (<10 kPa) are required in areas as diverse as blood-pressure monitoring, human-computer interactions, robotics, and object detection. For applications, it is essential that these sensors combine flexibility, high sensitivity, robustness, and low production costs. Previous works involve surface micro-patterning, electronic amplification (OFET), and hydrogels. However, these solutions are limited as they involve complex processes, large bias voltages, large energy consumption, or are sensitive to evaporation. Here, we report a major advance to solve the challenge of scalable, efficient and robust e-skin. We present an unconventional capacitive sensor based on composite foam materials filled with conductive carbon black particles. Owing to the elastic buckling of the foam pores, the sensitivity exceeds 35 kPa −1 for pressure <0.2 kPa. These performances are one order of magnitude higher than the ones previously reported. These materials are low-cost, easy to prepare, and display high capacitance values, which are easy to measure using low-cost electronics. These materials pave the road for the implementation of e-skin in commercialized applications. npj Flexible Electronics (2019) 3:7 ; https://doi.

Domaines: Chimie; Matériaux

Mickaël Pruvost, Wilbert Smit, Cécile Monteux, Philippe Poulin, Annie Colin. Polymeric foams for flexible and highly sensitive low-pressure capacitive sensors. npj Flexible Electronics, 2019, 3 (1), ⟨10.1038/s41528-019-0052-6⟩. ⟨hal-02321074⟩