Smart material

About: Smart material is a research topic. Over the lifetime, 3704 publications have been published within this topic receiving 74280 citations. The topic is also known as: intelligent material & responsive material.

4D printing of mechanically robust PLA/TPU/Fe3O4 magneto-responsive shape memory polymers for smart structures

Abstract: The integration of magneto-responsive shape memory polymers (SMPs) into 4D printing provides novel opportunities to create innovative and intelligent products controlled in a contactless method. In this study, a promising SMPs with robustly mechanical property and magneto-responsive behavior were proposed and fabricated into 3D printing feedstock based on polylactic acid (PLA), thermoplastic polyurethane (TPU) and Fe 3 O 4 particles. Results revealed that the 3D-printed PLA/TPU/Fe 3 O 4 possessed robust tensile strength and modulus with a homogeneous distribution of magnetic particles in polymer blends. Also, PLA/TPU/Fe 3 O 4 exhibited excellent shape fix ratio (∼100%), recovery ratio (>91%) and rapid magnetic response within as short as 40 s, suggesting the high efficiency of heat generation by magnetic particles. Moreover, smart structures including honeycomb and bionic flower-like model were designed and printed as an original shape. After programmed by an external force, the folded lattice structure at the temporary shape could recovered completely under a contactless magnetic field. The flower-bud structure sequentially restored layer-by-layer controlled by using three pedals with varied Fe 3 O 4 composites. Consequently, the high-load capacity, fast magneto-responsive behavior and high recovery performance of the proposed multi-material have great potentials in actuator or robots applications via 3D printing. • The PLA/TPU/Fe 3 O 4 composites with varying Fe 3 O 4 contents are capable to fabricate filaments for fused filament (FFF) 3D printing. • PLA/TPU/Fe 3 O 4 composite filaments show fast magneto-responsive shape memory and recovery behavior by heat or magneto stimulation. • Facile transformation are perfectly realized between designed structures with temporary shape fixed by heat or external force and then magneto-stimulated into original shape.

A simple statistical approach to model the time-dependent response of polymers with reversible cross-links.

Abstract: A new class of polymers characterized by dynamic cross-links is analyzed from a mechanical point of view. A thermodynamically consistent model is developed within the Lagrangian framework for polymers that can rearrange their internal cross-links. Such a class of polymers has the capability to reset their internal microstructure and the microscopic remodeling mechanism leads to a behavior similar to that of an elastic fluid. These materials can potentially be used in several fields, such as in biomechanics, smart materials, morphing materials to cite e few. However, a comprehensive understanding is necessary before we can predict their behavior and perform material design for advanced technologies. The proposed formulation-following a statistical approach adapted from classical rubber elasticitye is based on the evolution of the molecular chains' end-to-end distance distribution function. This distribution is allowed here to evolve with time, starting from an initial stress-free state and depending on the deformation history and the cross-link attachment/detachment kinetics. Some simple examples are finally presented and discussed to illustrate the capability and generality of the developed approach.

A remotely driven and controlled micro-gripper fabricated from light-induced deformation smart material

Abstract: Micro-gripper is an important tool to manipulate and assemble micro-scale objects. Generally, as micro-gripper is too small to be directly driven by general motors, it always needs special driving devices and suitable structure design. In this paper, two-finger micro-grippers are designed and fabricated, which utilize light-induced deformation smart material to make one of the two fingers. As the smart material is directly driven and controlled by remote lights instead of lines and motors, this light-driven mode simplifies the design of the two-finger micro-gripper and avoids special drivers and complex mechanical structure. In addition, a micro-manipulation experiment system is set up which is based on the light-driven micro-gripper. Experimental results show that this remotely light-driven micro-gripper has ability to manipulate and assemble micro-scale objects both in air and water. Furthermore, two micro-grippers can also work together for cooperation which can further enhance the assembly ability. On the other hand, this kind of remotely controllable micro-gripper that does not require on-board energy storage, can be used in mobile micro-robot as a manipulation hand.

Smart material motor with mechanical diodes

Abstract: The present invention is actuator having a shaft delivering mechanical power to a load, a first active element adapted to be driven by an oscillating signal, and at least one mechanical diode operatively connected to the shaft in the act of development. A plurality of mechanical diodes may also be used. Mechanical diodes can be either rotary mechanical diodes or linear mechanical diodes. The mechanical diodes can also be bi-directional.

Development of smart systems for building structures

Abstract: Building Research Institute, Japanese Ministry of Construction, initiated a 5-year research and development project of 'Smart Materials and Structural Systems' in 1998 as a part of U.S.-Japan cooperative research efforts. The U.S. Counterpart is the National Science Foundation. Smart Structural Systems (also called as Autoadaptive Media) are defined as systems that can automatically adjust structural characteristics, in response to the change in external disturbance and environments, toward structural safety and serviceability as well as the extension of structural service life. The research and development of (1) concept and performance evaluation of smart structure system, (2) sensing of structure performance, and (3) development and evaluation of structural elements using smart materials will be conducted.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.