Phys.org May 18, 2022 A team of researchers in the US (Pennsylvania State University, Michigan Technological University) developed and demonstrated a mechanism that enhances the magnitude of the piezoelectric coefficient of a ceramic. Through extensive characterization conducted using high-resolution microscopy and diffraction techniques in conjunction with the computational models they found that chemical heterogeneity and anisotropy are the underlying mechanisms that govern the piezoelectric performance of ceramic materials. They showed that by aligning all the grains in a ceramic material along certain crystallographic axes they could get a very high piezoelectric response. They achieved close to 2,000 picocoulombs per Newton. […]
Tag Archives: Advanced manufacturing
Scientists bioprint tissue-like constructs capable of controlled, complex shape change
Phys.org March 31, 2022 The development of hydrogel-based 4D bioinks, especially those allowing living cell printing, with easy preparation, defined composition, and controlled physical properties is critically important for 4D bioprinting. Researchers at the University of Illinois have developed a single-component jammed micro-flake hydrogel (MFH) system with heterogeneous size distribution, which differs from the conventional granular microgel as a new cell-laden bioink for 4D bioprinting. The cytocompatible MFH features scalable production and straightforward composition with shear-thinning, shear-yielding, and rapid self-healing properties. It can be smoothly printed into stable 3D bioconstructs, which can be further cross-linked to form a gradient in […]
Water as a ‘glue’ for elasticity enhanced, wet attachment of biomimetic structures
Phys.org March 29, 2022 Octopus, clingfish, and larva use soft cups to attach to surfaces under water. Using a novel micro cup, fabricated by two-photon lithography, coupled with in situ pressure sensor and observation cameras, an international team of researchers (Germany, USA – University of Illinois) has detailed the nature of its attachment/detachment under water. It involves elasticity-enhanced hydrodynamics generating “self-sealing” and high suction at the cup-substrate interface, converting water into “glue.” Detachment is mediated by seal breaking. They identified three distinct mechanisms of breaking including elastic buckling of the cup rim. A mathematical model described the interplay between the […]
With a little help, new optical material assembles itself
Phys.org February 4, 2022 To overcome a longstanding problem of molecular impurities in nanoscience a team of researchers in the US (MIT, UC Berkeley, Argonne National Laboratory) developed a new technique that coaxes diverse blends of polymers and nanoparticles into spontaneously forming tiny, nested rings within minutes of adding an impurity. They hypothesized that diversifying the blend’s composition can overcome these limitations. Increasing the number of components increases mixing entropy, leading to the dispersion of different components and, as a result, enhances interphase miscibility. The molecular migration would unlock the system’s entropy that helps to distribute the material’s building blocks, […]
Scientists weave atomically thin wires into ribbons
Phys.org January 31, 2022 Using tungsten telluride nanowires researchers in Japan created bundles of wires deposited on a flat substrate and exposed to vapors of chalcogens like sulfur, selenium, and tellurium. With a combination of heat and vapor, the initially separate threads in the bundles were successfully woven together into narrow, atomically thin nanoribbons with a characteristic zigzag structure. By tuning the thickness of the original bundles, they could even choose whether these ribbons were oriented parallel to the substrate or perpendicular to it. By tuning the substrate on which the bundles are placed, they could control whether the ribbons […]
Impossible material made possible inside a graphene sandwich
Nanowerk January 20, 2022 So far, only a few dozen 2D crystals have been extracted from materials that exhibit a layered phase in ambient conditions, omitting entirely the large number of layered materials that may exist at other temperatures and pressures. An international team of researchers (Austria, Germany, Slovakia, Belgium, France) synthesized 2D cuprous iodide that was stabilized in a graphene sandwich, as the first example of a material that does not otherwise exist in normal laboratory conditions. It normally only occurs in layered form at elevated temperatures between 645 and 675 K. The synthesis utilizes the large interlayer spacing […]
A pair of gold flakes creates a self-assembled resonator
Science Daily December 2, 2021 Self-ordering in molecular and biological systems typically involves short-range hydrophobic and van der Waals interactions. An international team of researchers (Sweden, Russia) has found a way process for micrometre-scale self-assembly based on the joint action of attractive Casimir and repulsive electrostatic forces arising between charged metallic nanoflakes in an aqueous solution. This system forms a self-assembled optical Fabry–Pérot microcavity with a fundamental mode in the visible range (long-range separation distance about 100–200 nanometres) and a tunable equilibrium configuration. By placing an excitonic material in the microcavity region, they were able to realize hybrid light–matter states […]
Researchers integrate optical devices made of multiple materials onto single chip
Science Daily September 29, 2021 An international team of researchers (UK, Italy, Australia) has developed transfer printing process and demonstrated its ability to place devices made of multiple materials on a single chip, all integrated within a footprint similar in size to the devices themselves. The method is based on reversible adhesion in which a device is picked up and released from its growth substrate and placed onto a new surface. The process uses a soft polymer stamp mounted on a robotic motion control stage to pick up an optical device from the substrate on which it was made. When […]
Just by changing its shape, scientists show they can alter material properties
Nanowerk September 13, 2021 An international team of researchers (USA – Argonne National Laboratory, University of Chicago, Israel) explored confined transport using a patterned structure in titania films, with feature sizes of 11–20 nm. They described how confinement changes the competing charge transport mechanisms, the patterned antidot array leads to displacement fields and confines the charge density that results in modified and emergent electron transport with an increase in conductivity. This emergent behavior can be described by considering electron interference effects. Characterization of the charge transport with electron holography and impedance spectroscopy, and through comparison with modeling, showed that nanoscale […]
GaN-on-diamond semiconductor material that can take the heat – 1000 C to be exact
Nanowerk September 9, 2021 Researchers in Japan used the surface activated bonding (SAB) method to successfully bond GaN and diamond and demonstrated that the bonding is stable even when heated to 1,000°C. A 5.3 nm-thick intermediate layer composed of amorphous carbon and diamond is formed at the as-bonded heterointerface. As the team increased annealing temperatures, the layer thickness decreased suggesting the intermediate layer can be completely removed by optimizing the annealing process. As no peeling was observed at the heterointerface after annealing at 1000°C these results indicate that the GaN/diamond heterointerface can withstand harsh fabrications processes. The material shows promise […]