Bio‐Inspired Stretchable, Adhesive, and Conductive Structural Color Film for Visually Flexible Electronics

Abstract

The rapid progress in flexible electronic devices has attracted immense interest in many applications, such as health monitoring devices, sensory skins, and implantable apparatus. Here, inspired by the adhesion features of mussels and the color shift mechanism of chameleons, a novel stretchable, adhesive, and conductive structural color film is presented for visually flexible electronics. The film is generated by adding a conductive carbon nanotubes polydopamine (PDA) filler into an elastic polyurethane (PU) inverse opal scaffold. Owing to the brilliant flexibility and inverse opal structure of the PU layer, the film shows stable stretchability and brilliant structural color. Besides, the catechol groups on PDA impart the film with high tissue adhesiveness and self‐healing capability. Notably, because of its responsiveness, the resultant film is endowed with color‐changing ability that responds to motions, which can function as dual‐signal soft human‐motion sensors for real‐time color‐sensing and electrical signal monitoring. These features make the bio‐inspired hydrogel‐based electronics highly potential in the flexible electronics field.

Suction Cups‐Inspired Adhesive Patch with Tailorable Patterns for Versatile Wound Healing

“…[ 3 ] The necessary properties of patches usually include good biocompatibility, effective adhesion, and flexible applicability. [ 4 ] Although many successes have been achieved in this area, rare patches could achieve these properties at the same time. Generally, most existing adhesive patches are made of bioharmful chemical derivative components and may induce allergic response, secondary skin damage, and contamination, [ 5 ] while patches from biosafe polymers typically have poor mechanical match with tissues.…”

Flexible Polydopamine Bioelectronics

“…[ 35–37 ] For example, Wang and co‐workers reported a dopamine (DA) monomer‐triggered gelation process toward flexible skin‐like sensors with desired adhesion, robust toughness, self‐healing ability, and thermal responsive feature. [ 38 ] Zhao's group combined PDA and inverse opal scaffolds to develop visually flexible bioelectronics as the color and electrical dual‐signal sensors, [ 39 ] and further expanded the scope to implantable cardiac patches that could real‐time monitor the heartbeat activity. [ 40 ] Considering the rapid growth and promising future of this filed, herein we strive to make a tutorial review paper that closely connects PDA properties with bioelectronic device performances.…”

Morphological Hydrogel Microfibers with MXene Encapsulation for Electronic Skin

“…Benefiting from dramatic progresses on the study of stretchable electronics, electronic skins have attracted considerable interests to both commercial development and the research community due to their potential applications in artificial intelligence systems [4,5], wearable health monitoring [6,7], human-machine interface [8,9], and other fields [10][11][12]. Nowadays, numerous electrical conductors, including ionic liquids [13,14], liquid metals [15,16], and other two-dimensional materials [17][18][19], have been integrated with stretchable sheets to respond to external stimuli and transmit corresponding electrical signals. Among those electrical conductors, MXenes [20,21], as one class of two-dimensional early-transition metal carbides/carbonitrides, have emerged with widespread attention due to their fascinating properties, such as large hydrophilic surfaces and excellent electrical/thermal conductivity.…”