Recent electronics technology development has provided unprecedented opportunities for enabling implantable bioelectronics for long-term disease monitoring and treatment. Current electronics-tissue interfaces are characterized by weak physical interactions, suffering from potential interfacial failure or dislocation during long-term application. On the other hand, some new technologies can be used to achieve robust electronics-tissue interfaces; however, such technologies are limited by potential risks and the discomfort associated with postdetachment of the bioelectronics. Here, a hydrogel-based electronicstissue interface based on the exploitation of dynamic interactions (such as boronate-diol complexation) that features an interfacial toughness over 400 J m −2 is presented. Moreover, these hydrogel adhesion layers are also triggerdetachable by dissociating the dynamic complexes (i.e., addition of glucose). These hydrogel-based bioelectronic interfaces enable the in vivo recording of physiological signals (i.e., electromyograph, blood pressure, or pulse rates). Upon mild triggering, these bioelectronics can be easily detached without causing any damage, trauma, or discomfort to the skin, tissues, and organs. This kind of trigger-detachable hydrogel adhesives offer general applicability in bioelectronic interfaces, exhibiting promising utility in monitoring, modulating, and treating diseases where temporary monitoring of physiologic signals, interfacial robustness, and postremoval of bioelectronics are required.

Hydrogel bioadhesion technology has offered unprecedented opportunities in minimally-invasive surgeries, which are routinely performed to reduce postoperative complication, recovery time, and patient discomfort. Existing hydrogelbased adhesives are challenged either by their inherent weak adhesion under wet and dynamic conditions, or potential immunological side-effects, especially for synthetic hydrogel bioadhesives. Here, a kind of synthetic hydrogel bioadhesives from a variety of polymer precursors are reported, featuring instant formation of tough biointerface, allowing for wet and robust adhesion with highly dynamic biological tissues. Moreover, by getting rid of monomers during the hydrogel fabrication, these hydrogel adhesives do not cause any inflammatory response during the in vivo wound sealing, promising for immediate vascular defects repairing and surgical hemostasis. Additionally, they could also serve as human-electronics interfacing materials, enabling bioelectronics implantation for real-time physiological and clinical monitoring.

Hydrogel bioadhesives have emerged as one of the most promising alternatives to sutures and staples for wound sealing and repairing, owing to their unique advantages in biocompatibility, mechanical compliance, and minimally invasive manipulation. However, only a few hydrogel bioadhesives have been successfully used for gastric perforation repair, due to their undesirable swelling when in direct contact with extremely acidic gastric fluids, and are thereby accompanied by a gradually deteriorating adhesion performance. Herein, an acid-tolerant hydrogel (ATGel) bioadhesive is developed, which integrates two distinct components, an acid-tolerant hydrogel substrate and an adhesive polymer brush layer. The ATGel bioadhesive can form instant, atraumatic, fluid-tight, and sutureless sealing of gastric perforation, and enable robust biointerfaces in direct contact with gastric fluids, addressing the key limitations with sutures and commercially-available tissue adhesives. Moreover, in vivo investigation on gastric perforation of rat model validates the proposed acid-tolerant bioadhesion, and identifies the mechanisms for accelerated gastric perforation repair through alleviated inflammation, which suppresses fibrosis and enhances angiogenesis.

Flexible and stretchable light emitting devices are driving innovation in myriad applications, such as wearable and functional electronics, displays and soft robotics. However, the development of flexible electroluminescent devices via conventional techniques remains laborious and cost-prohibitive. Here, we report a facile and easily-accessible route for fabricating a class of flexible electroluminescent devices and soft robotics via direct ink writing-based 3D printing. 3D printable ion conducting, electroluminescent and insulating dielectric inks were developed, enabling facile and on-demand creation of flexible and stretchable electroluminescent devices with good fidelity. Robust interfacial adhesion with the multilayer electroluminescent devices endowed the 3D printed devices with attractive electroluminescent performance. Integrated our 3D printed electroluminescent devices with a soft quadrupedal robot and sensing units, an artificial camouflage that can instantly self-adapt to the environment by displaying matching color was fabricated, laying an efficient framework for the next generation soft camouflages.

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23 MPa), despite its exceptionally high water content (i.e., 90 wt%). The integration of such unprecedented mechanical attributes is mainly ascribed to the exquisite multilayered lamellar structures consisting of aligned chitin nanofibers. [5,6] However, when compared with natural materials, conventional synthetic hydrogels are typically weak and fragile for practical applications, owing to the sparsely crosslinked network, low solid content, homogeneous structure, and absence of structural hierarchy, thus hampering their practical applications where long service life, high loading capability and/or impact tolerance are highly demanded. [7][8][9][10] One of the most promising approaches to engineer synthetic hydrogels with extraordinary mechanical properties (i.e., strength, modulus, toughness and fatigue resistance) is through the bioinspired structural hierarchy design. [10][11][12][13][14][15][16][17] The most spectacular examples are nacre-like polymer or hydrogel composites, which are consisted of aligned micro/nanoparticles in a polymer matrix, thus, enabling them stiff yet tough and able to dissipate energy. [5,[18][19][20][21][22][23] In addition to the layered and brick-and-mortar microstructures, high inorganic loading (i.e., >70 wt%) is another critical role for the mechanical enhancement, however, sacrificing With the strengthening capacity through harnessing multi-length-scale structural hierarchy, synthetic hydrogels hold tremendous promise as a low-cost and abundant material for applications demanding unprecedented mechanical robustness. However, integrating high impact resistance and high water content, yet superior softness, in a single hydrogel material still remains a grand challenge. Here, a simple, yet effective, strategy involving bidirectional freeze-casting and compression-annealing is reported, leading to a hierarchically structured hydrogel material. Rational engineering of the distinct 2D lamellar structures, well-defined nanocrystalline domains and robust interfacial interaction among the lamellae, synergistically contributes to a record-high ballistic energy absorption capability (i.e., 2.1 kJ m −1 ), without sacrificing their high water content (i.e., 85 wt%) and superior softness. Together with its low-cost and extraordinary energy dissipation capacity, the hydrogel materials present a durable alternative to conventional hydrogel materials for armor-like protection circumstances.

Floated pH-degradable PVA nanogels (FA-NGs) are developed for simultaneous delivery of DTX and IDO1-inhibitor N9 to enhance cancer chemo-immunotherapy.