Conventional epidermal bioelectronics usually do not conform well with natural skin surfaces and are susceptible to motion artifact interference, due to incompatible dimensions, insufficient adhesion, imperfect compliance, and usually require complex manufacturing and high costs. We propose in situ forming hydrogel electrodes or electronics (ISF-HEs) that can establish highly conformal interfaces on curved biological surfaces without auxiliary adhesions. The ISF-HEs also have favorable flexibility and soft compliance comparable to human skin (≈0.02 kPa–1), which can stably maintain synchronous movements with deformed skins. Thus, the as-prepared ISF-HEs can accurately monitor large and tiny human motions with short response time (≈180 ms), good biocompatibility, and excellent performance. The as-obtained nongapped hydrogel electrode-skin interfaces achieve ultralow interfacial impedance (≈50 KΩ), nearly an order of magnitude lower than commercial Ag|AgCl electrodes as well as other reported dry and wet electrodes, regardless of the intrinsic micro-obstacles (wrinkles, hair) and skin deformation interference. Therefore, the ISF-HEs can collect high-quality electrocardiography and surface electromyography (sEMG) signals, with high signal-to-noise ratio (SNR ≈ 32.04 dB), reduced signal crosstalk, and minimized motion artifact interference. Simultaneously monitoring human motions and sEMG signals have also been implemented for the general exercise status assessment, such as the shooting competition in the Olympics. The as-prepared ISF-HEs can be considered as supplements/substitutes of conventional electrodes in percutaneously noninvasive monitoring of multifunctional physiological signals for health and exercise status.

In 3D (bio)printing, it is critical to optimize the printing conditions to obtain scaffolds with designed structures and good uniformities. Traditional approaches for optimizing the parameters oftentimes rely on the prior knowledge of the operators and tedious optimization experiments, which can be both time‐consuming and labor‐intensive. Moreover, with the rapid increase in the types of biomaterial inks and the geometrical complexities of the scaffolds to be fabricated, such a traditional strategy may prove less effective. To address the challenge, an artificial intelligence‐assisted high‐throughput printing‐condition‐screening system (AI‐HTPCSS) is proposed, which is composed of a programmable pneumatic extrusion (bio)printer and an AI‐assisted image‐analysis algorithm. Based on the AI‐HTPCSS, the printing conditions for obtaining uniformly structured hydrogel architectures are screened in a high‐throughput manner. The results show that the scaffolds printed under the optimized conditions demonstrate satisfying mechanical properties, in vitro biological performances, and efficacy in accelerating the diabetic wound healing in vivo. The unique AI‐HTPCSS is expected to offer an enabling platform technology on streamlining the manufacturing of tissue‐engineering scaffolds through 3D (bio)printing techniques in the future.

The development of easy-to-use, low-cost, and visualized detection platforms for screening human dental caries and periodontal diseases is in urgent demand. In this work, a Au@Ag nanorods-poly(dimethylsiloxane) (Au@Ag NRs-PDMS) wearable mouthguard, which can visualize the tooth lesion sites through the color change of it at the corresponding locations, is presented. The Au@Ag NRs-PDMS composite exhibits a distinct color response to hydrogen sulfide (H 2 S) gas generated by bacterial decay at the lesion sites. Moreover, the Au@Ag NRs-PDMS mouthguard is demonstrated to own desired mechanical properties, excellent chemical stability, as well as good biocompatibility, and can accurately locate the lesion sites in human oral cavity. These findings suggest that the mouthguard has the potential to be utilized on a large scale to help people self-monitor their oral health in daily life, and treat oral diseases locally.

Cell-laden hydrogel microstructures have been used in broad applications in tissue engineering, translational medicine, and cell-based assays for pharmaceutical research. However, the construction of cell-laden hydrogel microstructures in vitro remains challenging. The technologies permitting generation of multicellular structures with different cellular compositions and spatial distributions are needed. Herein, we propose a laser-guided programmable hydrogel-microstructures-construction platform, allowing controllable and heterogeneous assembly of multiple cellular spheroids into spatially organized multicellular structures with good bioactivity. And the cell-laden hydrogel microstructures could be further leveraged for in vitro drug evaluation. We demonstrate that cells within hydrogels exhibit significantly higher half-maximal inhibitory concentration values against doxorubicin (DOX) compared with traditional 2D plate culture. Moreover, we reveal the differences in drug responses between heterogeneous and homogeneous cell-laden hydrogel microstructures, providing valuable insight into in vitro drug evaluation.