Hysteretic Buckling for Actuation of Magnet–Polymer Composites

Abstract

The development of bioinspired, novel, high-performance, "artifi cial muscle" materials is a topic of high current interest. Flexibility for folding and actuation are key parameters in the development of such artifi cial muscles, especially for self-assembly and origami engineering. A current challenge is to develop a multifunctional material that combines the biological functions of actuation, sensing, and healing. In this work, for the fi rst time experimental and modeling results of the actuation capability of a multifunctional magnet-polymer (Magpol) composite material that is already capable of damage sensing and self-healing are reported. Actuation by constrained buckling of Magpol in an external magnetic fi eld shows two buckling modes. The stress and strain are studied and optimized for various actuator geometries. Work density of up to 16 J kg −1 is obtained, comparable to electroactive polymers. Magpol is successfully able to lift more than four times its own weight at relatively low applied magnetic fi eld. Good agreement is observed between the experimental and modeling results. An Ashby design chart is employed to compare its performance to other actuators. This work provides insight into the development of next generation fl exible, active multifunctional materials.

In Situ Generated Medical Devices

“…Through magnetically controlled morphing operations, rapid response to contactless actuation has been achieved at high actuation strain, strain rate and self‐sensing. Furthermore, multicycle damage sensing, self‐healing and hysteretic buckling were also demonstrated …”

“…Ramanujan's earlier work demonstrated the twisting, bending, elongation, Curie temperature regulated heating, and self‐healing of MPCs, which are required for wireless and programmable in situ device fabrication of magnetic‐polymer composite medical devices (MPCMD) . In situ device fabrication and operation of MPCMD is illustrated in Figure .…”

“…The motion of MPCMDs can result in shrinkage, elongation, deformation, bending, or folding, as well as self‐healing or welding as schematically shown in Figure …”

Nonlinear displacement control of magnetic material actuators

“…In addition to battery-less operation, MPC actuators are capable of large strain and relatively high-frequency response [5]. Recent applications include drug delivery microrobots for precise dosage targeting [6], artificial muscle [7] and microfluidics [8]. As the interest in MPC actuators rise, and more applications are proposed, a growing concern is how to control material displacement accurately.…”

Design-based modeling of magnetically actuated soft diaphragm materials

“…MPC are easily processed into different (complex) geometries and are capable of large deformation, fast response and wireless actuation [14][15][16]. Existing applications of MPC in literature include artificial muscle [17,18], origami engineering [19,20] and microfluidics [21,22], to name a few.…”