A star in the world of ceramic engineering

Science Daily  February 10, 2022 A team of researchers in the US (Virginia Polytechnic Institute and State University, Bowdoin College, Harvard University) investigated the complex and highly ordered mineralized skeletal system of sea star from the tropical Indo-Pacific region. The skeleton consists of many millimeter-sized skeletal elements called ossicles which connect with soft tissue, allowing the animal to be flexible and move. Each ossicle is constructed of a microlattice structure so uniform that it can be described mathematically. They found that it is essentially a single crystal structure at atomic level which allows a sea star to reinforce its skeleton […]

Scientists engineer new material that can absorb and release enormous amounts of energy

Phys.org  February 2, 2022 Solid–solid phase transformations can affect energy transduction and change material properties. A team of researchers at UMass Amherst developed elasto-magnetic metamaterials that display phase transformation behaviors due to nonlinear interactions between internal elastic structures and embedded, macroscale magnetic domains. They also developed the design algorithms that allow these materials to be programmed with specific responses, making them predictable. Using predictive model, they developed a quantitative phase map that relates the geometry and magnetic interactions to the phase transformation. According to the researchers their work demonstrates that the new material holds great promise for a very wide […]

Bone growth inspired ‘microrobots’ that can create their own bone

Science Daily  January 17, 2022 Combining materials which together resemble the natural process of bone development an international team of researchers (Sweden, Japan) constructed a microrobot which can assume different shapes and change stiffness. They started with a gel material called alginate. On one side of the gel, they grew an electroactive polymer which changes its volume when a low voltage is applied, causing the microrobot to bend in a specified direction. On the other side of the gel, they attached biomolecules, that are important for bone development which allowed the soft gel material to harden. They demonstrated that the […]

This 3D-Printer Uses Ink Made From Microbes to Print Blobs That Are Alive

Science Alert December 1, 2021 Based on the living cells ability to synthesize molecular components and precisely assemble them to build living functional architectures under ambient conditions microbial engineering has produced materials for various applications. However, building 3D structures in arbitrary patterns and shapes has been a challenge. A team of researchers in the US (Harvard University, Northeastern University, Harvard Medical School) has developed a bioink (microbial ink) that is produced entirely from genetically engineered microbial cells, programmed to perform a bottom-up, hierarchical self-assembly of protein monomers into nanofibers, and nanofiber networks that comprise extrudable hydrogels. They demonstrated the 3D […]

‘Anti-aging’ chemistry taken from nature overcomes next-gen lithium battery decay

Phys.org  November 15, 2021 Degradation occurs pretty much everywhere in nature since oxygen is one of the elements most capable of attracting electrons from other atoms and molecules. Organisms often produce different types of enzymes that work to scavenge active oxygen and free radicals to alleviate the issue. Inspired by the anti-oxygen coping mechanisms in nature researchers in China developed a photostabilizer—a simple, anti-aging binder additive to the electrolyte that can scavenge the singlet oxygen atoms and free radicals as they occur. Through experimental investigation and theoretical calculation, they found that the scavenging mechanism in layered transition metal oxides-based lithium […]

Flexible, stretchable battery capable of moving smoothly like snake scales

Nanowerk  September 28, 2021 Researchers in South Korea have made a structure with individual, overlapping units, similar to snake scales that can be used to construct shape-morphing batteries for untethered soft robots. They created it by folding well-defined, two-dimensional patterns with cutouts, the folding lines mimicking the hinge structure of snakeskin, enabling stable deformations without mechanical damage to rigid cells. The structure is applied to a stretchable Li-ion battery, constructed to form an arrangement of electrically interconnected, hexagonal pouch cells. Simulation confirmed that the battery maintains its performance under dynamic deformation with a 90% stretching ratio and 10-mm-radius bending curve, […]

Unbreakable glass inspired by seashells

Phys.org  September 28, 2021 Nacre, mother of pearl, made of stiff pieces of chalk-like matter that are layered with highly elastic soft proteins, has the rigidity of a stiff material and durability of a soft material. It is 3000 times tougher than the materials that compose it. An international team of researchers (Canada, USA- University of Colorado) took the architecture of nacre and replicated it with layers of glass flakes and acrylic, yielding an exceptionally strong yet opaque material that can be produced easily and inexpensively. They made the composite optically transparent. By tuning the refractive index of the acrylic, […]

Winged microchip is smallest-ever human-made flying structure

Science Daily  September 22, 2021 An international team of researchers (South Korea, UK, USA – Northwestern University, University of Wisconsin, University of Connecticut, University of Illinois, University of Purdue, China, Hong Kong) studied wind-dispersed seeds to build microfliers and optimized its aerodynamics to ensure that it falls at a slow velocity in a controlled manner. They fabricated precursors to flying structures in flat, planar geometries and bonded them onto a slightly stretched rubber substrate. When the stretched substrate is relaxed, a controlled buckling process occurred causing the wings to “pop up” into precisely defined three-dimensional forms. It included sensors, a […]

Engineering a polymer network to act as active camouflage on demand

Phys.org  September 16, 2021 Despite extensive efforts to create colour-changing materials and devices, it is challenging to achieve pixelated structural coloration with broadband spectral shifts in a compact space. An international team of researchers (USA – University of Pennsylvania, South Korea) describes pneumatically inflating thin membranes of main-chain chiral nematic liquid crystalline elastomers that have such properties. By taking advantage of the large elasticity anisotropy and Poisson’s ratio (>0.5) of these materials, they geometrically programed the size and the layout of the encapsulated air channels to achieve colour shifting from near-infrared to ultraviolet wavelengths with less than 20% equi-biaxial transverse […]

World’s first discovery of liquid directional steering on a bio-inspired surface

Phys.org  September 16, 2021 A liquid deposited on a surface tends to move along directions that reduce surface energy, which is mainly dictated by surface properties rather than liquid properties, such as surface tension. Achieving well-controlled directional steering remains challenging because the liquid-solid interaction mainly occurs in the 2D domain. An international team of researchers (China, Hong Kong) has shown that the spreading direction of liquids with different surface tensions can be tailored by designing 3D capillary ratchets that create an asymmetric and 3D spreading profile both in and out of the surface plane. Such directional steering is also accompanied […]