Flexible and sensitive foot pad for sole distributed force detection

Abstract

Abstract² We develop highly flexible and compressible 3D interconnected porous PDMS structures by using sugar cubes as templates. The porous structures can be compressed to more than 80% without any side-wall buckling comparable with bulk polymers. Force sensitive resistors were fabricated by filtration of the CNT solution inside the porous structure of PDMS. We found that sufficient acid treatment can increase the adhesion and bonding between CNTs and PDMS. Force sensitive resistors respond the applied pressure and compressive strains by high linearity (R 2 >0.97) and sensitivity (GFs>2) with a reliable manner. Finally, as an application of our force sensitive resistors, a flexible foot pad containing force sensitive resistors arrays is developed for the foot sole distributed force detection. I. I NTRODUCTION Development of flexible, stretchable and wearable electronic devices has recently drawn tremendous attention due to their numerous applications in biomedicine and robotics [1-4]. For example, flexible, stretchable and wearable strain sensors were utilized for the human motion detection [1, 5]; artificial electronic skins were developed for the pressure sensing and visualization [2, 6]; ultra-thin flexible sensors were used for continues temperature monitoring of the human skin [7] or flexible and transparent batteries were employed for the endoscopy application [4].