Preparation and application of electrical conductive composites with skin temperature-triggered attachable and on-demand detachable adhesion

Electronic skin, represented by stretchable flexible strain sensors, is widely used to detect the movement of human joints, etc., because of its comfortable attachment to the skin. The strain sensors with adhesive properties are essential in terms of conformal attachment to skin and transmitting signals precisely. However, it is of great importance to develop flexible sensors with reversible attachment and detachment in practical applications. In this work, a novel skin temperature-triggering adhesive conductive composite was obtained by copolymerization of acrylate monomers stearyl acrylate (SA) and tetradecyl acrylate (TA) in situ with vinylsilane grafted carbon nanotubes (VCNTs) and carbon black (CB). The obtained composite has the characteristics of adjustable stiffness and adhesion by changing temperature due to the crystallizable alkyl side chain of SA and TA. Specifically, the composite exhibits adhesion at skin temperature and loses its adhesive properties at lower temperature due to the amorphous-to-semicrystalline phase transition of copolymer matrix. While the coordination of zero-dimensional (0D) CB and one-dimensional (1D) VCNTs imparts the composite good electrical conductivity of 3.6 × 10 6 Ω cm. The composite-based strain sensor displays stable monitor results of human motion. Therefore, this work might enrich the preparation strategies for flexible sensors in wearable electronic devices and electronic skin.