The creation of micromotors that can convert stored energy to autonomous movement would be of great value in various applications, ranging from chemical sensing to precision water-quality screening and from cleaning clogged arteries to repairing microscopic cracks. Many of micromotors, based on different propulsion mechanisms (e.g., magnetic fields, ultrasound filed, chemical fuels, light, and bubble propulsion), [1][2][3][4][5][6][7][8][9] have been designed and fabricated over the past decade. Generally, they are built of rigid materials [10] to maintain a good maneuverability, but often with limited body compliance and adaptability in confined spaces. [11][12][13] In contrast to the hard Shape-transformable liquid metal (LM) micromachines have attracted the attention of the scientific community over the past 5 years, but the inconvenience of transfer routes and the use of corrosive fuels have limited their potential applications. In this work, a shape-transformable LM micromotor that is fabricated by a simple, versatile ice-assisted transfer printing method is demonstrated, in which an ice layer is employed as a "sacrificial" substrate that can enable the direct transfer of LM micromotors to arbitrary target substrates conveniently. The resulting LM microswimmers display efficient propulsion of over 60 µm s −1 (≈3 bodylength s −1 ) under elliptically polarized magnetic fields, comparable to that of the common magnetic micro/ nanomotors with rigid bodies. Moreover, these LM micromotors can undergo dramatic morphological transformation in an aqueous environment under the irradiation of an alternating magnetic field. The ability to transform the shape and efficiently propel LM microswimmers holds great promise for chemical sensing, controlled cargo transport, materials science, and even artificial intelligence in ways that are not possible with rigid-bodies microrobots.bodied, nature has created a wide range of biological motors with deformable bodies at small scales. They often have strong ability to actively adapt to their environment, thus can perform various demanding tasks in complex environments. Inspired by nature, researchers have begun to explore the design and control shape-transformable micromotors composed of compliant materials [14,15] (e.g., hydrogels, [16] granular media, [17] lowmelting point alloys, [18,19] and electroactive polymers [14] ) to ensure maneuverability, adaptability and agility in practical applications. Liquid metals (LMs) are typical examples of highly extensible and adaptable compliant materials, [20,21] such as Gallium and gallium-containing alloys (e.g., eutectic gallium-indium (EGaIn): 75% gallium and 25% indium; Galinstan: 68.5% gallium, 21.5% indium, and 10% tin). One of the most striking features of these gallium-based liquid metals is the nearly instant formation of a passivating oxide layer on their surface in the present of oxygen. This oxide layer (mainly composed of Ga 2 O 3 ) mechanically stabilizes the liquid metals into nonequilibrium shapes [22] and can be removed ...

A bioinspired magnetically powered microswimmer is designed and experimentally demonstrated by mimicking the morphology of annelid worms. The structural parameters of the microswimmer, such as the surface wrinkling, can be controlled by applying prestrain on substrate for the precise fabrication and consistent performance of the microswimmers. The resulting annelid-worm-like microswimmers display efficient propulsion under an oscillating magnetic field, reaching a peak speed of ≈100 µm s . The speed and directionality of the microswimmer can be readily controlled by changing the parameters of the field inputs. Additionally, it is demonstrated that the microswimmers are able to transport microparticles toward a predefined destination, although the translation velocity is inevitably reduced due to the additional hydrodynamic resistance of the microparticles. These annelid-worm-like microswimmers have excellent mobility, good maneuverability, and strong transport capacity, and they hold considerable promise for diverse biomedical, chemical sensing, and environmental applications.

Magnetic shape memory alloys (MSMAs), both in condensed matter physics and in material science, are one of the most extensive research subjects. They show prompt response to the external magnetic field and give rise to large strain and have fine reversibility. The well-known example is Heusler-type MSMAs, which possess excellent multifunctional properties and have potential applications in energy transducer, actuator, sensor, microelectromechanical system, and magnetic refrigerator. In this paper, it is shown the recent progress in magnetostructural transformation, magnetic properties, shape deformation, magnetocaloric effect as well as magnetic field-induced shape memory effect in Ni-Mn-Ga, NiMnZ (Z = In, Sn, Sb), and NiCoMnZ (Z = In, Sn, Sb, Al) Heusler-type MSMAs. The remaining issues and possible challenges are briefly discussed.

Prussian blue materials have been considered as ideal cathodes for sodium-ion batteries (SIBs) because of the unique open framework structure. Among those, nickel hexacyanoferrate (NiHCF) with a “zero strain” characteristics...