An Elastic and Damage-Tolerant Dry Epidermal Patch with Robust Skin Adhesion for Bioelectronic Interfacing

Abstract

On-skin patches that record biopotential and biomechanical signals are essential for wearable healthcare monitoring, clinical treatment, and human−machine interaction. To acquire wearing comfort and high-quality signals, patches with tissue-like softness, elastic recovery, damage tolerance, and robust bioelectronic interface are highly desired yet challenging to achieve. Here, we report a dry epidermal patch made from a supramolecular polymer (SESA) and an in situ transferred carbon nanotubes' percolation network. The polymer possesses a hybrid structure of copolymerized permanent scaffold permeated by multiple dynamic interactions, which imparts a desired mechanical response transition from elastic recoil to energy dissipation with increased elongation. Such SESA-based patches are soft (Young's modulus ∼0.1 MPa) and elastic within physiologically relevant strain levels (97% elastic recovery at 50% tensile strain), intrinsically mechanical-electrical damage-resilient (∼90% restoration from damage after 5 min), and interference-immune in dynamic signal acquisition (stretch, underwater, sweat). We demonstrate its versatile physiological sensing applications, including electrocardiogram recording under various disturbances, machine-learning-enabled hand-gesture recognition through electromyogram measurement, subtle radial artery pulse, and drastic knee kinematics sensing. This epidermal patch offers a promising noninvasive, long-duration, and ambulant bioelectronic interfacing with anti-interference robustness.

Sustainable, Insoluble, and Photonic Cellulose Nanocrystal Patches for Calcium Ion Sensing in Sweat

“…[ 44 ] The characteristic CNC peaks of the COC band at 1138 cm −1 and CO stretching bands at 1081 and 1039 cm −1 shifted to lower wavenumbers (Figure 3c), suggesting the formation of intermolecular hydrogen bonds between CNC and PVA chains. [ 45 ]…”

“…[44] The characteristic CNC peaks of the COC band at 1138 cm −1 and CO stretching bands at 1081 and 1039 cm −1 shifted to lower wavenumbers (Figure 3c), suggesting the formation of intermolecular hydrogen bonds between CNC and PVA chains. [45] 2Dcos is a powerful tool for extracting finer spectral information. [46] To elucidate the dynamics of thermally induced dehydration and hydrogen bonding evolution, FTIR spectra collected at 20-60 and 60-100 °C, respectively, were further analyzed by 2Dcos (Figure 3d-g).…”

Solvent‐Free and Skin‐Like Supramolecular Ion‐Conductive Elastomers with Versatile Processability for Multifunctional Ionic Tattoos and On‐Skin Bioelectronics

“…The capture of the electrophysiological signals not only plays a vital role in clinical applications, but also is the key to construct humanmachine interfaces, which has become an active field with significant advances in non-clinical areas such as home/work automation, cognitive training, entertainment, and so forth. [18][19][20][21][22]39,[72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87] Our paintable I-tattoos, featuring exceptional stability and low electrode-skin IEI, are superb candidates as skin electrodes for the high-fidelity acquisition of various electrophysiological sig-nals. To monitor the ECG signals, I-tattoos were painted on the inner wrists of the right and left forearms of a volunteer, and the metal conductors were directly adhered to the I-tattoos without a cumbersome fixation system (Figure 6a).…”

“…Consequently, electronic tattoos (E-tattoos) including the sticker-type and paintable ones, [1,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] which exhibit ultraconformal contact and strong adhesion with human skin, have emerged as a superior alternative to E-skins for sensing and transmitting physiological signals. The fabrication of E-tattoos generally relies on elaborate engineering of the electronic conductors (e.g., metals, carbon nanomaterials, conductive polymers, liquid metals) to endow them with stretchability, patterned structures, and ultrathin nature.…”

“…The fabrication of E-tattoos generally relies on elaborate engineering of the electronic conductors (e.g., metals, carbon nanomaterials, conductive polymers, liquid metals) to endow them with stretchability, patterned structures, and ultrathin nature. [11][12][13][14][15][16][17][18][19][20][24][25][26] Hence, complicated and multi-step fabrication processes and/or high-cost conductive materials are always required, limiting the scalable production and widespread use of E-tattoos. In this scenario, a game-changing strategy is highly desirable to enable simple, convenient, and low-cost fabrication of tattoo-like on-skin bioelectronics, which however depends on the development of novel electrically conductive materials with skin-like properties.…”