Mechanically robust shape-morphing materials that can transform from miniaturization into complex structures are highly desirable for real-world device applications. However, fabricating mechanically robust yet geometrically complex 3D shape-morphing structures with excellent functionality and high load-bearing capacity remains a challenge. Inspired by drum tower buildings, a simple, rapid, and universal method is presented for fabricating multifunctional shape-memory smart devices with complex and rigid 3D kirigami geometry in the two-stage epoxy-amine-acrylate photopolymer systems. In the first-stage reaction, transparent polymer films with a T g of 29–49 °C are obtained by the epoxy-amine chemistry. The shape-memory programming process allows the first-stage film with a drum tower-inspired 2D kirigami pattern to be manipulated into an unsupported 3D structure. In the second-stage reaction, UV-induced free-radical polymerization of methacrylate groups in the first-stage network is employed to rapidly lock the programmed 3D kirigami structure with a T g of 66–138 °C. The drum tower-inspired 3D kirigami structure withstands 1000 times its own weight. The shape memory fluorescent 3D device and shape memory electronic 3D device are engineered by combining the two-stage photopolymer system and a 3D kirigami structure. This work represents a versatile method to create multifunctional shape-memory devices with rigid 3D geometry for potential applications.
Nowadays quantitative chemical analysis is usually costly, instrument-dependent, and time-consuming, which limits its implementation for remote locations and resource-limited regions. Inspired by the ancient papercutting art (kirigami), we herein introduce a novel cut-and-paste protocol to fabricate 3D microfluidic paper-based analytical devices (μPADs) that are suitable for on-site quantitative assay applications. The preparation of the device is fast, simple, and independent of any lithographic devices or masks. Particularly designed reaction “channels” were pre-cut from a piece of filter paper, then assembled back to the silanized, superhydrophobic paper pads. The different layers of the device were assembled using a chemically-inert adhesive spray. The fabricated device has high efficiency of liquid handling (up to 60 times faster than conventional methods) and it is particularly inexpensive. Beyond the benchtop fabrication advantage, in conjunction with a custom mobile app developed for colorimetric analysis, we were able to quantify representative environmental contaminants (i.e., the amount of Cr(VI) and nitrite ions) in various water samples with the cut-and-paste μPADs (namely kPADs). Their detection limits (0.7 μg mL−1 for Cr(VI) and 0.4 μg mL−1 for nitrite ions, respectively) are comparable with conventional spectrophotometric methods, which confirm the potential of kPADs for on-site environmental/sanitary monitoring and food toxin pre-screening.
危险品化学品经营许可证（带存储）