Mechanical nonreciprocity in a uniform composite material

Abstract

Mechanical nonreciprocity, or the asymmetric transmission of mechanical quantities between two points in space, is crucial for developing systems that can guide, damp, and control mechanical energy. We report a uniform composite hydrogel that displays substantial mechanical nonreciprocity, owing to direction-dependent buckling of embedded nanofillers. This material exhibits an elastic modulus more than 60 times higher when sheared in one direction compared with the opposite direction. Consequently, it can transform symmetric vibrations into asymmetric ones that are applicable for mass transport and energy harvest. Furthermore, it exhibits an asymmetric deformation when subjected to local interactions, which can induce directional motion of various objects, including macroscopic objects and even small living creatures. This material could promote the development of nonreciprocal systems for practical applications such as energy conversion and biological manipulation.

Anisotropic Polybenzimidazole Ion‐Solvating Membranes Composed of Aligned Nano‐Sheets for Efficient Acid‐Alkaline Amphoteric Water Electrolysis

“…The oriented alignment of PBI nano‐sheets could be further supported by the 2D SAXS images in Figure 2G, confirming the anisotropic nature of PBI‐aNS. [ 14 ] There were SAXS peaks observed at the d‐spacing of 11.6 and 5.5 nm for PBI‐Gel membranes (Figure S5C, Supporting Information), which were shifted to the d‐spacing ≈9.8 and 3.1 nm in PBI‐aNS (Figure S5D, Supporting Information). These peaks may correspond to the 15 nm filament bundle sizes and the distance between nano‐sheets or nano‐filaments.…”

Polymer mechanochemistry: from single molecule to bulk material

“…Polymers, such as rubber, elastomer, and gel, are widely used in various everyday applications including gloves, tires, packaging materials, coatings, contact lenses, medical devices, flexible electronics, and engineering composites, due to their lightweight nature and unique mechanical properties such as high mechanical strength, toughness, elasticity and processability. 1–3 Understanding the influence of external mechanical force on the stability and properties of polymeric materials has long been an important field of study for determining their in-use performances. 4–6 Macroscopic mechanical forces applied to polymeric materials like stretching, indentation, compression and shear loading are known to be transferred to an individual elastically active chain, resulting in various physical and chemical reactions such as scission of covalent bonds and noncovalent interactions.…”

Indirect Adhesion of Hydrogels via the Radical Polymerization Mediated by N,N,N′,N′-Tetramethylethylenediamine and Ammonium Persulfate

“…Hydrogel materials − have attracted much attention from various fields including engineering , and medication , because they are composed of a huge amount of water, which is one of the most environmentally friendly materials and biocompatible materials on earth, in addition to polymeric networks. Until now, various hydrogel materials having excellent and interesting properties, such as tough hydrogels, − self-oscillating gels, , and others, , have been reported. It is supposed that these hydrogel materials have high potential for soft actuators, , soft robots, , soft electric devices, − artificial biomaterials, , and other various applications. − When we use hydrogels for these applications, adhesive hydrogel systems are important because it is necessary to make hydrogels adhere with other hydrogels or other substrates when we use them for these applications.…”