These materials are typically combined using one of the following three general strategies (see Supplementary Table 1 for details). metallic particles (e.g., liquid metal 3, 28, 29, 30, 31, 32, silver 33, gold 34), carbon allotropes 35, 36, or soft electrically conductive composites (e.g., polyaniline 37, polypyrrole 38, PEDOT:PSS 39). Conductive materials used in soft electromagnetic devices include liquid metal 13, 14, 15, 16, 17, 18, 19, 20, 21, serpentine copper/gold patterns 4, 22, 23, 24, 25, 26, 27, or conductive composites consisting of a soft polymer matrix and a conductive dispersion phase, e.g. Magnetoactive materials are usually made of soft elastomers embedded with ferromagnetic particles that are magnetized with a programmed magnetization profile 11, 12. These emerging classes of material systems have the potential for transformative impact in a variety of application domains, including soft robotics 3, 4, wearable computing 5, 6, 7, 8, and biomedical devices 9, 10.Ĭurrent approaches to creating soft electromagnetic devices are based on heterogeneous combinations of magnetoactive elastomer composites and conductive materials. Soft electromagnetic devices combine magnetic and electrical functionality with intrinsic mechanical compliance to achieve robust elasticity along with remote actuation, sensing, and energy harvesting 1, 2. Our work thus provides a material design strategy for soft electromagnetic devices with unexplored hybrid functions. To demonstrate the great potential of MME devices, precise and minimally invasive electro-ablation was performed with a flexible MME catheter with magnetic control, hybrid actuation-sensing was performed by a durable somatosensory MME gripper, and hybrid wireless energy transmission and magnetic actuation were demonstrated by an untethered soft MME robot. Assisted by the coaxial printing method, the MME fiber can be printed into complex 2D/3D MME structures with integrated magnetoactive and conductive properties, further enabling hybrid functions including programmable magnetization, somatosensory, and magnetic actuation along with simultaneous wireless energy transfer.

Here, we report a hybrid magnetic-mechanical-electrical (MME) core-sheath fiber to overcome these challenges. However, existing soft-magneto-electrical devices would have limited hybrid functions and suffer from damaging stress concentrations, delamination or material leakage. Soft electromagnetic devices have great potential in soft robotics and biomedical applications.

Flux integral of rectangle