Fig. 5: Examples of bioadhesive devices demonstrating stable tissue interfacing capabilities through various material strategies and manufacturing technologies.

a The schematic illustration for in situ diagnosis process of overactive bladder rat model. b Photographs showing the attached ultra-soft hydrogel combined with structurally engineered islets (USH-SI) sensor onto the bladder. (Scale bar = 10 mm) c Plot accumulated urine volume and intra-bladder pressure (IBP), strain sensor resistance and EMG RMS. Reproduced with permission from ref. ¹⁸⁹ (a–c). d Schematic illustration of the absorption of the interfacial water by densified activated nanoparticles (ANP) and the formation of nanohesion (top) and the interactions between ANP and surfaces through short-range forces (bottom). e The in vivo fixation procedure of strain sensor. (Scale bar = 2 mm) f Pulse signals acquired by a nanohesive-fixed strain sensor with simultaneous ECG signals. g Comparison of pulse rates from ECG and nanohesive-fixed strain sensors over 30 min. Reproduced with permission from ref. ¹⁹² (d–g). h Schematic illustration of the polymer hydrogel bioadhesvie (PHB) enabling robust biointerfaces for wireless sensors. i Measurements of f₀ during squeezing and releasing of a rat flank validate the reliability of the PHB-based biointerface. Reproduced with permission from ref. ¹⁹⁵ (h, i). j Schematic illustration a bioelectronic device’s physical attachment to tissue. k Images of epicardial ECG recordings at day 0, day 14, and on-demand detachment of bioadhesive electrodes. l Surface ECG signals from needle electrodes compared to epicardial ECG signals recorded by bioadhesive electrodes at day 0 and day 14. Reproduced with permission from ref. ¹⁹⁶ (j–l). m Schematic illustration of 3D printing-based fabrication of the adhesive bioelectronic interface. n Images of the implanted all-hydrogel bioelectronic interfaces on rat heart. o Epicardial recordings from hydrogel interfaces at day 28 post-implantation. Reproduced with permission from ref. ¹⁷⁰ (m–o). p Adhesive attachment using BASC channels with wet tissues, enabled by semiconducting and adhesive polymers for robust covalent bonding. q Schematic illustration of device structure of the adhesive OECT under strain. Scale bar, 5 mm. r Stable attachment of a adhesive OECT to gastrocnemius medialis (GM) muscle during mechanical agitation, compared to non-adhesive OECT, with corresponding EMG recordings. Reproduced with permission from ref. ¹⁹⁷ (p–r). s Images of ultraconformal brain adhesion of shape-morphing cortex-adhesive (SMCA) sensors on curved surfaces of ex vivo bovine cortex. t–u Electrocorticogram recordings comparing PDMS (t) and SMCA (u) sensors under tFUS stimulation. Reproduced with permission from ref. ²⁰⁰ (s–u). v Wet-resistant adhesion of the electrospun self-healing polymer (SHP) network (E-SHN) with Alg-CA on cardiac tissue during washing. w Bidirectional interfacing via Alg-CA coatings between tissues and EGaIn composites, shown with ECG signals during rat heart stimulation. Reproduced with permission from ref. ²⁰¹ (v–w).