Functional Asymmetry-Enabled Self-Adhesive Film via Phase Separation of Binary Polymer Mixtures for Soft Bio-Integrated Electronics

Abstract

Biocompatible adhesive films are important for many applications (e.g., wearable devices, implantable devices, and attachable sensors). In particular, achieving self-adhesion on one side of a film with biocompatible materials is a compelling goal in adhesion science. Herein, we report a simple and easy manufacturing process using water-soluble hyaluronic acid (HA) that allows adhesiveness on only one side using binary polymer mixtures based on a phase-separation strategy with an elastomer. HA influx allows for the entangled polymer chains of the elastomer to spontaneously deform, permitting tunable mechanical elasticity, conformability, and adhesion. The proposed adhesive film enables the transfer of nanopatterning and the attachment of various surfaces without the use of additional chemicals. In addition, the film can be used for measuring epidermal biopotential and for skin fixation of drug devices. Therefore, the developed facile asymmetric adhesion can block the interferences of other materials on the unnecessary adhesion side, providing considerable potential for the development of functional, multifunctional, and smart bioadhesives.

Illuminating Recent Progress in Nanotransfer Printing: Core Principles, Emerging Applications, and Future Perspectives

“…This mold strippingbased F mold weakening can be done by selectively etching polymeric molds while leaving the inorganic target materials on the substrate. [19,75,76] For example, Ahn et al fabricated the 3D nanostructures by buckling Au nanowires on a pre-stretched PDMS substrate. [19] Here, they prepared Au nanowires on nanopatterned poly(urethane acrylate) (PUA) mold by e-beam evaporation.…”

“…In the simplest method, similar to the conventional tape based on the pressure-sensitive adhesive, the contact face of the substrate has been fabricated with an adhesive-like feature and utilized in nTP. [57,75,85] For example, Wang et al utilized a tape as the substrate for the nTP process. [85] They directly transferred the target material to the tape (substrate) and used it as a flexible and wearable nanophotonic device.…”

“…In the simplest method, similar to the conventional tape based on the pressure‐sensitive adhesive, the contact face of the substrate has been fabricated with an adhesive‐like feature and utilized in nTP. [ 57,75,85 ] For example, Wang et al. utilized a tape as the substrate for the nTP process.…”

Recent Advances in Sensor–Actuator Hybrid Soft Systems: Core Advantages, Intelligent Applications, and Future Perspectives

“…Over the past decade, soft systems comprising one or more soft transducers such as sensors, [ 1 , 2 , 3 , 4 ] actuators, [ 5 , 6 , 7 , 8 , 9 ] heaters, [ 10 ] and energy harvesters [ 11 ] have attracted significant attention because of their wide range of applications, including human motion monitoring, [ 12 , 13 , 14 , 15 , 16 , 17 ] structural health monitoring, [ 18 ] artificial muscles, [ 19 ] and human–robot interaction systems. [ 20 , 21 ] Recently, studies on sensor‐actuator hybrid systems have been actively conducted to exploit the synergistic functions of individual devices, owing to the increasing demand for highly advanced and intelligent systems in soft devices.…”

Mechanical Slowing Down of Network-Forming Phase Separation of Polymer Solutions

“…Phase separation is of fundamental importance in fields covering soft matter, − biological systems, − and industrial applications of nanoporous materials. − Recently, the significance of phase separation in polymeric systems has experienced a renewed surge of interest from both fundamental and applied perspectives . Notably, phase separation plays a critical role in the biological functions of cells, highlighting its essentiality in the field of biology .…”