Self‐Healable and Recyclable Tactile Force Sensors with Post‐Tunable Sensitivity

Abstract

It is challenging to post‐tune the sensitivity of a tactile force sensor. Herein, a facile method is reported to tailor the sensing properties of conductive polymer composites by utilizing the liquid‐like property of dynamic polymer matrix at low strain rates. The idea is demonstrated using dynamic polymer composites (CB/dPDMS) made via evaporation‐induced gelation of the suspending toluene solution of carbon black (CB) and acid‐catalyzed dynamic polydimethylsiloxane (dPDMS). The dPDMS matrices allow CB to redistribute to change the sensitivity of materials at the liquid‐like state, but exhibit typical solid‐like behavior and thus can be used as strain sensors at normal strain rates. It is shown that the gauge factor of the polymer composites can be easily post‐tuned from 1.4 to 51.5. In addition, the dynamic polymer matrices also endow the composites with interesting self‐healing ability and recyclability. Therefore, it is envisioned that this method can be useful in the design of various novel tactile sensing materials for many applications.

Improved Sensitivity of Flexible Conductive Composites Throughout the Working Strain Range Based on Bioinspired Strain Redistribution

“…(d) GF of low-strain and maximum GF as a function of heterogeneous TC modulus difference; (inset) improvement of GF in the low-strain range. (e) GF comparison with reported literature. ,− (f) a 1 and a 2 as a function of Young’s modulus difference of heterogeneous TCs.…”

Micro‐Nano Processing of Active Layers in Flexible Tactile Sensors via Template Methods: A Review

“…Besides the earliest semiconductor materials, [43][44][45] composite materials formed by mixing conductive fillers with polymer matrixes have received a burgeoning amount of interest in recent years. Conductive fillers are generally divided into three categories: carbonbased materials (graphene, [46][47][48] carbon black, [49,50] carbon nanotubes, [51,52] Mxene, [53] etc. ), metal materials (Cu/Au/Ag nanomaterials [54][55][56][57] ), conductive polymers (poly(3,4-ethylenedioxythiophene), [58,59] polypyrrole (PPy), [60,61] etc.).…”

Reversibly growing crosslinked polymers with programmable sizes and properties

“…The acidic species retained their activity after polymerization and could easily percolate throughout the networks to distribute uniformly and even escape from the sample (Supplementary Figure 2) [13][14][15]45,46 . To prevent their evaporation and percolation, llers like carbon black (CB) and silica particles (SiO 2 ) that would adsorb acidic molecules on their surfaces 47 (Supplementary Figure 3-5) could be selectively added into the materials. The obtained materials were similar to normal silicone elastomers and could swell upon the uptake of the mixture of their parent monomer and crosslinker (nutrient solution).…”