natural behavior, many works have been done to realize reconfigurable shape transformation with artificial soft materials in a controlled manner. [8][9][10][11] Heterogeneous structures composited of hydrogel constituents with different swelling/shrinkage ratio [12][13][14][15][16] or anisotropic swelling behavior [17,18] have been constructed to accomplish dynamic tunable morphologies. Large shape deformation is shown in photodeformable crosslinked liquid crystal polymer through the orientation change of liquid crystal molecules, [19][20][21][22] and thus light-driven movable microarchitecture can be obtained. Inflation of elastic polymers constrained by relative stiff materials are applied to realize reconfigurable shape transformation. [23][24][25] These aforementioned shape reconfigurable materials are highly desired for many applications in soft robotics, [23,24] smart textiles, [26] drug delivery, [27] self-shaping devices, [28] and actuators. [22,29] Although nature-inspired artificial dynamic architectures have been widely studied as referred above, so far most of the shape transformation are dependent on the whole material deformation due to the technical challenge to locally induce shape change in a bulk material. Efforts have been taken to achieve dynamic structural behavior such as self-folding through modification of the localized properties of active materials, but these can only be done in macroscale by embedding Architectures of natural organisms especially plants largely determine their response to varying external conditions. Nature-inspired shape transformation of artificial materials has motivated academic research for decades due to wide applications in smart textiles, actuators, soft robotics, and drug delivery. A "self-growth" method of controlling femtosecond laser scanning on the surface of a prestretched shape-memory polymer to realize microscale localized reconfigurable architectures transformation is introduced. It is discovered that microstructures can grow out of the original surface by intentional control of localized laser heating and ablation, and resultant structures can be further tuned by adopting an asymmetric laser scanning strategy. A distinguished paradigm of reconfigurable architectures is demonstrated by combining the flexible and programmable laser technique with a smart shape-memory polymer. Proof-of-concept experiments are performed respectively in information encryption/decryption, and microtarget capturing/ release. The findings reveal new capacities of architectures with smart surfaces in various interdisciplinary fields including anti-counterfeiting, microstructure printing, and ultrasensitive detection.

Development of tunable microlenses by taking advantage of the physical adaptability of fluids is one of the challenges of optofluidic techniques, since it offers many applications in biochips, consumer electronics, and medical engineering. Current optofluidic tuning methods using electrowetting or pneumatic pressure typically suffer from high complexity involving external electromechanical actuating devices and limited tuning performance. In this paper, a novel and simple tuning method is proposed that changes the liquid refractive index in an optofluidic channel while leaving the shape of the microlens unchanged. To create an optofluidic microlens with high robustness and optical performance, built‐in microlenses are fabricated inside 3D glass microfluidic channels by optimized single‐operation wet etching assisted by a femtosecond laser. Tuning of focusing properties is demonstrated by filling the channel with media having different indices. Continuous tuning over a wide range (more than threefold tunability for both focal length and focal spot size) is also achieved by pumping sucrose solutions with different concentrations into the microchip channels. Reversible tuning is experimentally verified, indicating intriguing properties of the all‐glass optofluidic microchip. Both the proposed tuning method and the all‐glass architecture with built‐in microlens offer great potential toward numerous applications, including microfluidic adaptive imaging and biomedical sensing.

Rapid integration of high-quality functional devices in microchannels is in highly demand for miniature lab-on-a-chip applications. This paper demonstrates the embellishment of existing microfluidic devices with integrated micropatterns via femtosecond laser MRAF-based holographic patterning (MHP) microfabrication, which proves two-photon polymerization (TPP) based on spatial light modulator (SLM) to be a rapid and powerful technology for chip functionalization. Optimized mixed region amplitude freedom (MRAF) algorithm has been used to generate high-quality shaped focus field. Base on the optimized parameters, a single-exposure approach is developed to fabricate 200 × 200 μm microstructure arrays in less than 240 ms. Moreover, microtraps, QR code and letters are integrated into a microdevice by the advanced method for particles capture and device identification. These results indicate that such a holographic laser embellishment of microfluidic devices is simple, flexible and easy to access, which has great potential in lab-on-a-chip applications of biological culture, chemical analyses and optofluidic devices.

Structured laser beam based microfabrication technology provides a rapid and flexible way to create some special microstructures. As an important member in the propagation of invariant structured optical fields, Mathieu beams (MBs) exhibit regular intensity distribution and diverse controllable parameters, which makes it extremely suitable for flexible fabrication of functional microstructures. In this study, MBs are generated by a phase-only spatial light modulator (SLM) and used for femtosecond laser two-photon polymerization (TPP) fabrication. Based on structured beams, a dynamic holographic processing method for controllable three-dimensional (3D) microcage fabrication has been presented. MBs with diverse intensity distributions are generated by controlling the phase factors imprinted on MBs with a SLM, including feature parity, ellipticity parameter q, and integer m. The focusing properties of MBs in a high numerical aperture laser microfabrication system are theoretically and experimentally investigated. On this basis, complex two-dimensional microstructures and functional 3D microcages are rapidly and flexibly fabricated by the controllable patterned focus, which enhances the fabrication speed by 2 orders of magnitude compared with conventional single-point TPP. The fabricated microcages act as a nontrivial tool for trapping and sorting microparticles with different sizes. Finally, culturing of budding yeasts is investigated with these microcages, which demonstrates its application as 3D cell culture scaffolds.

Multilayered microfluidic channels integrated with functional microcomponents are the general trend of future biochips, which is similar to the history of Si-integrated circuits from the planer to the three-dimensional (3D) configuration, since they offer miniaturization while increasing the integration degree and diversifying the applications in the reaction, catalysis, and cell cultures. In this paper, an optimized hybrid processing technology is proposed to create true multilayered microchips, by which “ all-in-one” 3D microchips can be fabricated with a successive procedure of 3D glass micromachining by femtosecond-laser-assisted wet etching (FLAE) and the integration of microcomponents into the fabricated microchannels by two-photon polymerization (TPP). To create the multilayered microchannels at different depths in glass substrates (the top layer was embedded at 200 μm below the surface, and the underlying layers were constructed with a 200-μm spacing) with high uniformity and quality, the laser power density (13~16.9 TW/cm 2 ) was optimized to fabricate different layers. To simultaneously complete the etching of each layer, which is also important to ensure the high uniformity, the control layers (nonlaser exposed regions) were prepared at the upper ends of the longitudinal channels. Solvents with different dyes were used to verify that each layer was isolated from the others. The high-quality integration was ensured by quantitatively investigating the experimental conditions in TPP, including the prebaking time (18~40 h), laser power density (2.52~3.36 TW/cm 2 ) and developing time (0.8~4 h), all of which were optimized for each channel formed at different depths. Finally, the eight-layered microfluidic channels integrated with polymer microstructures were successfully fabricated to demonstrate the unique capability of this hybrid technique.

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Dong Wu, Koji Sugioka, and co‐workers (see article number https://doi.org/10.1002/adom.201701299) create all‐glass optofluidic microchips consisting of built‐in microlenses with high robustness and optical performance by optimized single‐operation femtosecond laser assisted etching. A novel and simple tuning method is also developed via changing the liquid refractive indices while leaving the shape of the microlenses unchanged.