Inspired by the diverse wrinkled surface patterns in nature, micro-nano scale wrinkled surfaces have become an essential part of materials science. Nowadays, it is still a challenge to flexibly fabricate three-dimensional (3D) nanowrinkled structures with precise configuration. Herein, we introduce a reaction-diffusion-based self-organized Turing mechanism integrated with femtosecond laser direct writing (FsLDW) to achieve controlled anisotropic photopolymerization, fabricating 3D hydrogel-based biomimetic Turing nanowrinkled structures. This approach enables precise spatial modulation of wrinkle periodicity, orientation, and amplitude. Furthermore, using methacrylated hyaluronic acid (MeHA) monomers, we elucidate the mechanistic interplay between anisotropic photopolymerization and Turing-patterned nanowrinkle formation. We further propose a theoretical framework—the polarization modulation of femtosecond laser pulses enables the anisotropic photopolymerization of Turing-patterned nanowrinkles, selectively generating aligned linear (Turing-line) and vertically ordered pillar (Turing-column) structures. According to this theoretical framework, we propose the concept of the nanowrinkle parameter (Wr), alongside an empirical formula derived from two-photon polymerization (TPP) fabrication parameters to predict Turing nanowrinkle emergence conditions. We also demonstrate the ability to create high-resolution, 3D nanowrinkled structures, including patterned structures, bio-inspired microvilli resembling those of the small intestine, cicada wing replicas, and moth-eye structures. Moreover, we functionalize Turing-patterned structures with magnetron-sputtered Ag coatings, creating micro/nano-devices for molecular surface enhanced Raman scattering (SERS) detection. The Turing-inspired SERS devices demonstrate ultra-trace detection capability for Rhodamine 6G (R6G) at concentrations as low as 10⁻⁹ M. This work provides a novel, high-precision methodology for the fabrication of complex, bionic, free-form Turing nanowrinkled structures.

Microrobots play an essential role in early diagnosis and precision medicine with the increasing demands for controllability in bio-medicine and micromanipulation, which can complete the pre-designed behavior under external stimulation. However, most microrobots are currently made of a single material system and focus on fabricating a driving module as the main structure of microrobots. This hinders the integration of diverse functions in one microrobot to fulfill the complex application. Here, a multi-material and multi-module hand-microrobot based on femtosecond laser direct writing technology is proposed, which has a pH-responsive capturing module and a magnetic-responsive transportation module (MRTM). This microrobot can not only respond to pH for capturing and releasing objects, but also respond to magnetic fields for cargo delivery even with obstacles. The two responding modules of the hand-microrobot are fabricated independently, and can collaborate with each other to achieve the delivery of target objects like polystyrene (PS) microsphere (10 μm) or 786-O cell by capturing, transporting, and spatial rolling. Besides, the MRTM can be locally fabricated on any prefabricated static structure, so that the whole microrobot can achieve controllable motion. This strategy is expected to be used to manipulate cells, deliver drugs for precise treatment, and environmental treatment.

Chitosan (CS)-based nanocomposites have been studied in various fields, requiring a more facile and efficient technique to fabricate nanoparticles with customized structures. In this study, Ag@methacrylamide CS/poly(ethylene glycol) diacrylate (Ag@MP) micropatterns are successfully fabricated by femtosecond laser maskless optical projection lithography (Fs-MOPL) for the first time. The formation mechanism of core-shell nanomaterial is demonstrated by the local surface plasmon resonances and the nucleation and growth theory. Amino and hydroxyl groups greatly affect the number of Ag@MP nanocomposites, which is further verified by replacing MCS with methacrylated bovine serum albumin and hyaluronic acid methacryloyl, respectively. Besides, the performance of the surface-enhanced Raman scattering, cytotoxicity, cell proliferation, and antibacterial was investigated on Ag@MP micropatterns. Therefore, the proposed protocol to prepare hydrogel core-shell micropattern by the home-built Fs-MOPL technique is prospective for potential applications in the biomedical and biotechnological fields, such as biosensors, cell imaging, and antimicrobial.