Tough Carbon Nanotube‐Implanted Bioinspired Three‐Dimensional Electrical Adhesive for Isotropically Stretchable Water‐Repellent Bioelectronics

Abstract

Integrated bioelectronics with conformal adhesion interfaces on dry/wet biosurfaces and water‐repellent stretchable electric elements are in high demand for reliable real‐time diagnostics of the dynamic human body. Here, the authors present a diving beetle‐inspired electro‐adhesive patch with mechanically robust nanowire‐implanted conductive multiscale architectures that provides a skin‐adaptable, isotropically stretchable interface for a multiple‐biosignal monitoring device. Using a facile all‐solution‐based process, a hydrophobic, stretchable carbon‐nanotube‐implanted conductive composite electrode on insect‐like adhesive architectures is fabricated. The conductive adhesive patch with bioinspired wrinkled microsuction cups exhibits remarkable enhanced wet adhesion with sweat‐drainability, as well as high stretchable electrical performance under tensile strain in dry and wet conditions. Owing to the high durability and softness of the bioinspired electric adhesive patch, its performance is successfully maintained even with repeated attachment (<1000 cycles) and mechanical stretching. To demonstrate a multiplexed wearable device, a temperature‐sensitive conductive material is coated onto the isotropically strain‐insensitive stretchable electrode to allow simultaneous electrocardiogram and temperature measurements on soft skin in dry and wet environments.

Aquatic Skin Enabled by Multi‐Modality Iontronic Sensing

“…It is directly mounted onto the wrist or instep of a healthy volunteer, where the arteries are superficial and the pulse waveforms are palpable, through a biocompatible adhesive, which could be replaced by novel underwater adhesives with longterm stability and biosecurity. [54] Figure 5b summarizes tactile measurements of the arterial pulse waveforms by the aquatic skin before and after underwater exercise. An increased heart rate has been observed from 72 to 110 BPM, accompanied with a substantially elevated pulse magnitude of the skin pressure from 1.0 to 2.4 kPa, accordingly.…”

Bioinspired carbon nanotube-based materials

“…application of bioinspired CNT-based materials in nanopatterned surfaces. 132,133 Liz-Marza ´n et al reported classical sea-anemonelike CNT-based hollow capsules with magnetic and reinforced properties. The CNT-coated Fe 3 O 4 NP@PS spheres were used as the ''hair'' to provide the reinforcement.…”

“…Besides their potential as reinforcing materials with high mechanical strength and chemical stability, the unique nanoscale morphology, low hydrophilicity, and optical characteristics of assembled structures of CNTs are also instructive for the application of bioinspired CNT-based materials in nanopatterned surfaces. 132,133 Liz-Marzán et al reported classical sea-anemone-like CNT-based hollow capsules with magnetic and reinforced properties. The CNT-coated Fe 3 O 4 NP@PS spheres were used as the “hair” to provide the reinforcement.…”

Bio-inspired adhesion control with liquids

“…Bio-inspired surfaces having specific wet-adhesive properties are already used in a variety of application fields (Ahn 2017;Baik et al, 2019;Chen et al 2018aChen et al , 2018bChen et al , 2019Liu et al, 2021;Wang et al 2018aWang et al , 2020bWang and Hensel 2021). For example, they can be employed as portable drug delivery patches for eye treatment (Than et al, 2018;Yang et al, 2013) and micromotors for stomach care (Cai et al, 2022), wearable flexible devices for the monitoring of physiological conditions of humans (Chun et al, 2018;Kim et al 2019Kim et al , 2021Lee et al, 2021;Min et al, 2021), and as medical tapes for wound treatment (Chen and Yang 2017;Peng et al, 2021) and skin care (Baik et al, 2021). They can be also used as the adhesive pads for bionic robots, as adhesive devices for the transport of liquid droplets in intelligent manufacturing (Chen et al, 2018b;Li et al, 2020), as wet adhesives for the repair of pipes and as smart tapes for micro/nanofilm transfer (Figure 2) (Lee et al, 2016;Park et al, 2021;Yi et al, 2018).…”