Large Field-like Spin-Orbit Torque and Enhanced Magnetization Switching Efficiency Utilizing Amorphous Mo.

Spin-orbit torque magnetic random access memory (SOT-MRAM) has great promise in high write speed and low power consumption. Mo can play a vital role in constructing a CoFeB/MgO-based MRAM cell because of its ability to enhance the perpendicular magnetic anisotropy (PMA), thermal tolerance, and tunneling magnetoresistance. However, Mo is often considered as a less favorable candidate among SOT materials because of its weak spin-orbit coupling. In this study, we experimentally investigate the SOT efficiencies in Mo/CoFeB/MgO heterostructures over a wide range of Mo thicknesses and temperature. Decent damping-like SOT efficiency |ξDL| = 0.015 ± 0.001 and field-like SOT efficiency |ξFL| = 0.050 ± 0.001 are found in amorphous Mo. The ξFL/ξDL ratio is greater than 3. Furthermore, efficient current-induced magnetization switching is demonstrated with the critical current density comparable with heavy metal Ir and W. Our work reveals new understanding and possibilities for Mo as both an SOT source component and PMA buffer layer in the implementation of SOT-MRAMs.

Reprogrammable, intelligent soft origami LEGO coupling actuation, computation, and sensing.

Tightly integrating actuation, computation, and sensing in soft materials allows soft robots to respond autonomously to their environments. However, fusing these capabilities within a single soft module in an efficient, programmable, and compatible way is still a significant challenge. Here, we introduce a strategy for integrating actuation, computation, and sensing capabilities in soft origami. Unified and plug-and-play soft origami modules can be reconfigured into diverse morphologies with specific functions or reprogrammed into a variety of soft logic circuits, similar to LEGO bricks. We built an untethered autonomous soft turtle that is able to sense stimuli, store data, process information, and perform swimming movements. The function multiplexing and signal compatibility of the origami minimize the number of soft devices, thereby reducing the complexity and redundancy of soft robots. Moreover, this origami also exhibits strong damage resistance and high durability. We envision that this work will offer an effective way to readily create on-demand soft robots that can operate in unknown environments.

Directional Transport of Underwater Bubbles on Solid Substrates: Principles and Applications.

The manipulation of underwater bubbles on substrates has received extensive research interest from both the scientific community and industry, including the chemical industry, machinery, biology, medicine, and other fields. Recent advances in "smart" substrates have enabled the bubbles to be transported on demand. Herein, the progress in the directional transport of underwater bubbles on various types of substrates is summarized, including planes, wires, and cones. The transport mechanism can be classified as buoyancy-driven, Laplace-pressure-difference-driven, and external-force-driven according to the driven force of the bubble. Moreover, the wide applications of directional bubble transport are reported, ranging from gas collection, microbubble reaction, bubble detection and classification, bubble switch, and bubble microrobots. Lastly, the advantages and challenges of various directional bubble transportation methods are discussed, and the current challenges and future prospects in this field are also discussed. This Review outlines the fundamental mechanisms of underwater bubble transportation on solid substrates and helps to understand the methods of optimizing bubble transportation performances.