Skin Adhesives with Controlled Adhesion by Polymer Chain Mobility

Abstract

Wearable devices have attracted a lot of attention because of their importance in the biomedical and electronic fields. However, as one of the important fixing materials, skin adhesives with controlled adhesion are often ignored. Although remarkable progress has been achieved in revealing the natural adhesion mechanism and biomimetic materials to complex solid surfaces, it remains a great challenge to explore nonirritant, controlled skin adhesives without surface structure. Herein, we present skin-adhesive patches of polydimethylsiloxanes (SAPs) with controlled adhesion by simply modulating polymer chain mobility at the molecular level. The controlled adhesion of SAPs strongly depends on the proportion of polymer chains with different mobility exposed to the solid surface, including free chains, dangling chains, and cross-linking chains. As a proof of concept, we demonstrate that the SAP can act as a skin-friendly fix to monitor the human pulse by integrating with the poly(vinylidene fluoride-trifluorethylene)/ reduced graphene oxide (P(VDF-TrFE)@rGO) nanofiber sensor. This study provides a clue to design durable and skin-friendly adhesives with controlled adhesion for wearable devices.

Sublethal exposure of small few-layer graphene promotes metabolic alterations in human skin cells

“…Although genotoxicity assays are still required, the results of this work show the relevance of refining our roadmap for interpreting data for a better understanding of the interactions between different GRMs and human barriers, with particular attention paid to metabolism and mitochondria even when an evident phenotype is not noticeable. These studies are also important because some GRMs have already been proposed for use in contact with skin, for example in textiles 29 or wearable electronics 30 , 31 . Special care must be taken to study the degradation and release of these materials during service life.…”

Asymmetric Janus adhesive tape prepared by interfacial hydrosilylation for wet/dry amphibious adhesion

“…However, the contradiction between the good mechanical and adhesion properties of PDMS restricts its practical application as a skin adhesive material. In contrast to our previous work 45 , we solved this contradiction by integrating lightly and highly crosslinked PDMS with an interfacial hydrosilylation reaction and first revealed its underwater adhesion properties. Our Janus adhesive tape with simultaneous strong wet/dry adhesion and high strength may provide an alternative candidate material to replace traditional homogeneous tapes.…”

“…In fact, if not pressed very hard, our Janus adhesive tape will leave little residue on the surface. Even if residue appears, in vitro cell culture 44 and skin experiments 45 have indicated the low cytotoxicity and good biocompatibility 46 of residual PDMS. The different surface topographies on silicon wafers could be attributed to the different polymer chain mobilities of these three tapes (Fig.…”

Breathable Nanowood Biofilms as Guiding Layer for Green On‐Skin Electronics

“…In addition, our biofilms inherit the bendability from wood slice (Figure S5, Supporting Information), facilitating the on‐skin adherence. Also, the massive –OH groups (evidenced by the FTIR peak at 3346 cm −1 , Figure S2, Supporting Information) make our biofilms adhere easily to the “sweating” surface of the skin (the adhesion of skin adhesives depends on the free polymer chains on the adhesive surface). Altogether, covering our biofilms with a multifunctional electrical L‐rGO layer would enhance the compressive resistance and tensile resistance ⊥ , the impressive tensile resistance // and bendability make our biofilms competent for applications in On‐skinE.…”