Magnetoelectronics for Magnetically Aware Soft-Bodied Robots

Motion sensing is the primary task in numerous disciplines including industrial and soft robotics, prosthetics, virtual and augmented reality appliances. In rigid electronics, rotations, displacements and vibrations are typically monitored using magnetic field sensors. Here, we will discuss on the fabrication of flexible, stretchable and printable magnetoelectronic devices. The technology platform relies on high-performance magnetoresistive and Hall effect sensors either deposited or printed on polymeric foils. These skin conformal flexible and printable magnetosensitive elements enable touchless interactivity with surroundings based on the interaction with magnetic fields. This is relevant for soft robotics [1] and human-machine interfaces based on smart skins [2-4] and smart wearables [5]. In particular, reconfigurable magnetic origami actuators [1] can be equipped with ultrathin and lightweight magnetosensitive e-skins [6], which help to assess the magnetic state of the actuator (magnetized vs. non-magnetized), decide on its actuation pattern and control sequentiality and quality of the folding process. The on-board sensing adds awareness to soft-bodied magnetic actuators enabling them to act and be controlled similar to conventional robotic devices [7]. Magnetic soft robots can be designed to perform complex collaborative tasks being driven using magnetic far fields [1] and near fields [8]. The use of magnetic near fields of on-board electromagnetic coils to drive embedded permanent magnets can provide the demanded tuneability to the mechanical strength of grippers working with objects of different stiffness including biological tissues [9]. Furthermore, we will introduce printed magnetic field sensors that can be flexible [10], stretchable [4], and capable of detection in a broad range of magnetic fields. By an appropriate choice of the polymeric binder, these solution processable magnetoelectronics can self-heal upon mechanical damage [11]. This research motivates further explorations towards the realisation of eco-sustainable magnetoelectronics. To this end, we will discuss biocompatible and biodegradable magnetosensitive devices, which can help to minimise electronic waste and bring magnetoelectronics to new application fields in medical implants and health monitoring.<br/><br/>[1] M. Ha et al., Reconfigurable magnetic origami actuators with on-board sensing for guided assembly. Adv. Mater. 33, 2008751 (2021).<br/>[2] G. S. Canon Bermudez et al., Electronic-skin compasses for geomagnetic field driven artificial magnetoreception and interactive electronics. Nature Electronics 1, 589 (2018).<br/>[3] J. Ge et al., A bimodal soft electronic skin for tactile and touchless interaction in real time. Nature Communications 10, 4405 (2019).<br/>[4] M. Ha et al., Adv. Mater. 33, 2005521 (2021).<br/>[5] P. Makushko et al., Flexible magnetoreceptor with tunable Intrinsic logic for on-skin touchless human-machine interfaces. Adv. Funct. Mat. 31, 2101089 (2021).<br/>[6] G. S. Canon Bermudez et al., Magnetosensitive e-skins for interactive devices. Adv. Funct. Mater. (Review) 31, 2007788 (2021).<br/>[7] E. S. Oliveros Mata et al., Magnetically aware actuating composites: Sensing features as inspiration for the next step in advanced magnetic soft robotics. Phys. Rev. Appl. (Review) 20, 060501 (2023).<br/>[8] M. Richter et al., Locally addressable energy efficient actuation of magnetic soft actuator array systems. Advanced Science 2302077 (2023).<br/>[9] L. Masjosthusmann et al., Miniaturized Variable Stiffness Gripper Locally Actuated by Magnetic Fields. <i>Advanced Intelligent Systems</i> 2400037 (2024).<br/>[10] E. S. Oliveros Mata et al., Dispenser printed bismuth-based magnetic field sensors with non-saturating large magnetoresistance for touchless interactive surfaces. Adv. Mater. Technol. 7, 2200227 (2022).<br/>[11] R. Xu et al., Self-healable printed magnetic field sensors using alternating magnetic fields. Nature Communications 13, 6587 (2022).