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On the basis of the complexity of the extracellular matrix, it is very important to control the threedimensional (3D) biochemical and physical properties of hydrogels at the microscale level. In this study, we demonstrated a synthetic strategy to construct biomimetic hydrogels (HA-MMP) for 3D cell culture that uses thiol-Michael chemistry to encapsulate cells in situ, o-nitrobenzyl alcohol photochemistry (a photogenerated-aldehyde-amineligation sequence, which is also referred to as a PAAL sequence) to permit biochemical patterning, and an enzymecleavable reaction to facilitate cell-responsive degradation in hydrogels. The effects of biochemical and mechanical parameters on 3D cell culture were studied using a userprogrammed Boolean logic-based algorithm, which provided an "AND" logic gate for cell survival, spreading, and migration. Finally, using the spatial controllability of light, cell-instructive 3D microenvironments can be constructed to guide cell behavior in hydrogels. This approach enables the versatile nature of chemistry to create programmable niches in hydrogels, which provides valuable insights into the cell fate by changing the local hydrogel microenvironments.

Micro/nano optoelectronic devices based on curved substrates play a significant role in the development of wearable devices, electronic skin, conformal sensors, conformal antennas, and soft robots. However, the current fabrication processes are oriented toward planar micro/nano devices, and the fabrication of such devices on curved substrates is challenging. Herein, a temperature‐gradient‐assisted nanoimprint‐based in situ micro/nano‐crystal growth method is proposed to fabricate high‐quality curved perovskite microwire crystal (MWC) arrays on curved surfaces. Based on this curved perovskite MWC array without bending‐induced defects, high‐performance curved photodetectors (responsivity = 414 A W−1, detectivity = 1.2 × 1014 Jones, and external quantum efficiency over 140 000%) with extraordinary stability (85% of original performance maintained for more than 2 years) are fabricated to realize a curved imaging device. These results provide insights into the application of high‐performance perovskite photodetectors in nonconformal optical systems.

Assembling perovskites into heterojunctions is an effective approach to achieve high‐performance photodetectors. Compared with vertical heterojunctions, in lateral heterojunction‐based photodetectors, the reflection loss is reduced because the active layer is in direct contact with light resulting in higher performance and better stability. However, lateral perovskite–perovskite heterojunctions are difficult to achieve using solution methods because the first formed film is easily dissolved by the solvent of the second precursor. In this study, a two‐step imprinting method is developed to fabricate lateral MAPbI3–MAPbBr3 microwire heterojunctions and realize a high‐performance photodetector with a responsivity and detectivity of 1207 A W−1 and 2.78 × 1013 Jones, respectively. At 0 V bias, the device exhibits a responsivity of up to 233 A W−1, which is more than double the previously reported best results. The high‐quality heterojunction endows the photodetectors with ultra‐high polarization sensitivity (Imax/Imin = 8.2) and long‐term stability, retaining 88.2% of its initial performance even after being exposed to air for 391 d.

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