Room-temperature creation and manipulation of skyrmions in MgO/FeNiB/Mo multilayers

Magnetic skyrmions in multilayer structures are considered as a new direction for the next generation of storage due to their small size,strong anti-interference ability,high current-driven mobility,and compatibility with existing spintronic technology.In this work,we present a tunable room temperature skyrmion platform based on multilayer stacks of MgO/FeNiB/Mo.We systematically studied the creation of magnetic skyrmions in MgO/FeNiB/Mo multilayer structures with perpendicular magnetic anisotropy(PMA).In these structures,the magnetic anisotropy changes from PMA to in-plane magnetic anisotropy(IMA)as the thickness of FeNiB layer increases.By adjusting the applied magnetic field and electric current,stable and high-density skyrmions can be obtained in the material system.The discovery of this material broadens the exploration of new materials for skyrmion and promotes the development of spintronic devices based on skyrmions.

Non-volatile multi-state magnetic domain transformation in a Hall balance

High performance of the generation,stabilization and manipulation of magnetic skyrmions prompts the application of topological multilayers in spintronic devices.Skyrmions in synthetic antiferromagnets(SAF)have been considered as a promising alternative to overcome the limitations of ferromagnetic skyrmions,such as the skyrmion Hall effect and stray magnetic field.Here,by using the Lorentz transmission electron microscopy,the interconversion between the single domain,labyrinth domain and skyrmion state can be observed by the combined manipulation of electric current and magnetic field in a Hall balance(a SAF with the core structure of[Co/Pt]_(4)/NiO/[Co/Pt]_(4)showing perpendicular magnetic anisotropy).Furthermore,high-density room temperature skyrmions can be stabilized at zero field while the external stimulus is removed and the skyrmion density is tunable.The generation and manipulation method of skyrmions in Hall balance in this study opens up a promising way to engineer SAF-skyrmion-based memory devices.

Different manipulation mode analysis of a radial symmetrical hexapod robot with leg-arm integration

With the widespread application of legged robot in various fields,the demand for a robot with high locomotion and manipulation ability is increasing.Adding an extra arm is a useful but general method for a legged robot to obtain manipulation ability.Hence,this paper proposes a novel hexapod robot with two integrated leg–arm limbs that obtain dexterous manipulation functions besides locomotion ability without adding an extra arm.The manipulation modes can be divided into coordinated manipulation condition and single-limb manipulation condition.The former condition mainly includes fixed coordinated clamping case and fixed coordinated shearing case.For the fixed coordinated clamping case,the degrees of freedom(DOFs)analysis of equivalent parallel mechanism by using screw theory and the constraint equation of two integrated limbs are established.For the fixed coordinated shearing case,the coordinated working space is determined,and an ideal coordinated manipulation ball is presented to guide the coordinated shearing task.In addition,the constraint analysis of two adjacent integrated limbs is performed.Then,mobile manipulation with one integrated leg–arm limb while using pentapod gait is discussed as the single-limb manipulation condition,including gait switching analysis between hexapod gait and pentapod gait,different pentapod gaits analysis,and a complex six-DOF manipulation while walking.Corresponding experiments are implemented,including clamping tasks with two integrated limbs,coordinated shearing task by using two integrated limbs,and mobile manipulation with pentapod gait.This robot provides a new approach to building a multifunctional locomotion platform.