Drum Tower‐Inspired Kirigami Structures for Rapid Fabrication of Multifunctional Shape‐Memory Smart Devices with Complex and Rigid 3D Geometry in a Two‐Stage Photopolymer

Abstract

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 Tg 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 Tg 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.

Reprocessable, Self-Healing, Thermadapt Shape Memory Polycaprolactone via Robust Ester–Ester Interchanges Toward Kirigami-Tailored 4D Medical Devices

“…ε load and ε represent the respective strains at the plasticity temperature before and after load removal, respectively . The shape fixity ratio ( R f ) and shape recovery ratio ( R r ) were calculated using the following equations: R f = ε d /ε m and R r = (ε d – ε rec )/ε d , where ε m and ε rec , respectively, represent the maximum strain under load and the recovered strain, and ε d is the fixed strain after cooling and load removal …”

Highly Stretchable, Biodegradable, and Recyclable Green Electronic Substrates

“…Kirigami is an ancient Chinese folk art that can form a variety of visually enjoyable patterns through cutting. [47,48] The combination of kirigami and industrial design can greatly broaden the design freedom of complex structures and enable new performance and functionality. [49] Inspired by the Chinese traditional tower and combined with kirigami, programmable AMW@CR-SBGC kirigami structures were designed, which can switch freely between 2D and 3D structures (Figure 6a).…”

Modeling Phase Separation of Free-Radical Polymerizations in Crosslinked Networks

“…Two-stage polymerizations have found extensive use in the field of polymeric materials. In particular, two-stage polymerizations are common in lithography, shape memory and fixity, additive manufacturing, holography, and interpenetrating networks (IPNs). , For a two-stage polymerization, two orthogonal polymerization chemistries with orthogonal stimuli or disparate time scales are present together in a resin. A first stimulus is applied to react one set of monomers into a loosely crosslinked network, followed by the introduction of a second stimulus or longer time-scale reaction to create a subsequent, independent polymerization in the system.…”