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Diphenylalanine (FF) demonstrates a robust ability to self‐assemble at the nanoscale forming a variety of structures ranging from nanospheres to nano‐ and microtubes resulting in outstanding functional properties including pyro‐ and piezoelectricity. FF nanotubes mimic the structure of β‐amyloid fibrils characteristic of Alzheimer's disease and thus can serve as a model material in biology and medicine. In this work, we report experimental proof that water trapped inside nanotubes exhibits dielectric properties similar to that of bulk water despite being confined in an ∼1 nm internal cavity. FF peptides thus provide a suitable template for the stabilization of the tetrahedral configuration of bulk water. Several phase transitions were observed via broadband dielectric spectroscopy and differential scanning calorimetry. Of these, two glass transitions at 205 K and 133 K related to different phases of water were found. The presence of α‐relaxation in the so‐called “no man's land” leads to a global glass transition at Tg = 133 K and structural phase transition at 230 K characteristic of tetrahedral water. The characterized collective response of water dipoles to an external electric field renders high pyro‐ and piezoelectric activity and non‐linear optical effects in FF dipeptides, conferring polarization‐dependent functionality to this important class of biomaterials.

peer-reviewed A disruptive method of fabricating free-standing tapes of La-doped (BaCaSrPb)TiO3 thermistors is demonstrated. The greatest advantage is that the free-standing tapes do not require high temperature co-firing of electrodes or reduced environment cofiring soft oxidation cycle to obtain thermal sensitivity. The approach thus solves the longstanding problem with the ceramic thermistor technology that eluded its compatibility with surface mount technology (SMT) and miniaturization. Stencil printing is employed that can fabricate up to 500 µm thick tapes in a single step, saving huge cost and processing steps for application requiring thicker films. The pastes suitable for freestanding tapes are reported. The method provides a novel route to integrate PTC elements into the chips of passive components and would lead to a massive reduction in cold resistivity when developed in multilayer laminated stacks.

The positive temperature co-efficient (PTC) of resistivity in BaTiO3 is a grain boundary effect, where the resistivity increases by several orders of magnitude near the transition temperature from ...

peer-reviewed The full text of this article will not be available in ULIR until the embargo expires on the 22/06/2020 This is a pre-print of an article that was published in " Computers In Biology And Medicine" for the final version please see http://dx.doi.org/10.1016/j.compbiomed.2019.103337 Planning and practice of surgical procedures can be improved through the use of modelling. This study provides an insight into the biopsy needle (i.e. hollow cannula) and needle-tissue interactions using a modelling approach, thus enabling the optimization of needle-tip designs not only for training but also for the planning of surgical procedures. Simulations of needle insertion into agar gel were performed using a Coupled Eulerian-Lagrangian (CEL) based finite element (FE) analysis, adapted for large deformation and tissue fracture. The experimental work covers needle insertion into 3% agar gel using a needle with a beveled tip of various angles, to assess the validity of the simulation. The simulated needle deflection and insertion force for two needles (i.e. Needle 1 with 18° bevel angle and Needle 2 with 27° bevel angle) were compared with corresponding experimental results. The contact stress (i.e. contact pressure) on the needles from the agar gel during the insertion of the needles were also studied. Observations indicate that varying the needle bevel angle from 27° to 18° results in a decrease of the peak force (i.e. puncture force) and an increase in needle deflection. Quantitatively, the percentage errors between the experimental data and the FE model for the total insertion force along the z-direction (i.e. Z Force) for Needle 1 and 2 were 4% and 4.8% (p > 0.05), respectively. Similarly, needle deflection percentage errors along the x-z plane were 5.7% and 10% respectively. Therefore, the forces and needle deflection values predicted by the simulation are a close approximation of the experimental model, validating the Coupled Eulerian-Lagrangian based FE model. Thus, providing an experimentally validated model for biopsy and cytology needle design in silico that has the potential to replace the current build and break approach of needle design used by manufacturers. peer-reviewed

peer-reviewed The full text of this article will not be available in ULIR until the embargo expires on the 28/10/2021 Water is a key solvent, fundamental to supporting life on earth. It is equally important in many industrial processes, particularly within agricultural and pharmaceutical industries, which are major drivers of the global economy. The results of water contamination by common activity in these industries is well known and EU Water Quality Directives and Associated Regulations mandate that NH4+ concentrations in effluent streams should not exceed 0.3 mg L−1, this has put immense pressure on organisations and individuals operating in these industries. As the environmental and financial costs associated with water purification begin to mount, there is a great need for novel processes and materials (particularly renewable) to transform the industry. Current solutions have evolved from combating toxic sludge to the use of membrane technology, but it is well known that the production of these membrane technologies creates a large environmental footprint. Zeolites could provide an answer; their pore size and chemistry enable efficient removal of aqueous based cations via simple ion exchange processes. Herein, we demonstrate efficient removal of NH4+ via both static and dynamic methodology for industrial application. Molecular modelling was used to determine the cation–framework interactions which will enable customisation and design of superior sorbents for NH4+ capture in wastewater.

Peptide assemblies are ideal components for eco-friendly optoelectronic energy harvesting devices due to their intrinsic biocompatibility, ease of fabrication, and flexible functionalization. However, to date, their practical applications have been limited due to the difficulty in obtaining stable, high-performance devices. Here, it is shown that the tryptophan-based simplest peptide cycloglycine-tryptophan (cyclo-GW) forms mechanically robust (elastic modulus up to 24.0 GPa) and thermally stable up to 370 °C monoclinic crystals, due to a supramolecular packing combining dense parallel β-sheet hydrogen bonding and herringbone edge-to-face aromatic interactions. The directional and extensive driving forces further confer unique optical properties, including aggregation-induced blue emission and unusual stable photo-luminescence. Moreover, the crystals produce a high and sustained opencircuit voltage (1.2 V) due to a high piezoelectric coefficient of 14.1 pC N(−1). These findings demonstrate the feasibility of utilizing self-assembling peptides for fabrication of biointegrated microdevices that combine high structural stability, tailored optoelectronics, and significant energy harvesting properties.

Classical Grand Canonical Monte Carlo (GCMC), classical molecular dynamics (MD), and density functional theory (DFT) have been employed to study the effect of pore-size and pore-chemistry on the adsorption of carbon dioxide in the SIFSIX-3-M family of hybrid ultramicroporous materials (HUMs), where M = Zn2+, Ni2+, or Cu2+. These HUMs have been shown to exhibit exceptional affinity toward small polarizable molecules such as CO2, and our simulated isotherms are in good agreement with those obtained experimentally. Isosteric heats of adsorption (Qst) calculated using these theoretical methods also follow the experimentally observed trend, decreasing as M varies from Cu to Ni to Zn in SIFSIX-3-M. More specifically, the interaction energy between a CO2 molecule and HUMs with varying pore-size was calculated using a DFT-D2 level of theory. The strongest interaction energy was calculated for SIFSIX-3-Cu (56.89 kJ mol–1) where the pore-size is the smallest. The interaction energy decreased in SIFSIX-3-Ni (52.21 k...

Ternary NiTiPt is of great interest in the biomedical industry with the potential to replace binary NiTi in implanted devices due to the alloy’s compatibility with medical imaging techniques and higher radiopacity. Cohesive and elastic properties are important for the processability and formability of materials using various hot and cold work methods. First principles simulations using density functional theory are reported here to determine the theoretical cohesive and elastic properties of NiTiPt with particular focus on nickel-rich stoichiometry. It has been found that Ni-rich NiTiPt alloy can form energetically stable cubic B 2 phase, but only up to a platinum content of around 18.75 at.%. On the other hand, the titanium-rich composition can keep the B 2 symmetry throughout the 0–50 at.% Pt range. Based on the observed trend in the elastic moduli cubic → orthorhombic → monoclinic phase transition has been suggested for both Ni-rich and Ti-rich compositions. With increasing platinum content the nickel-rich alloy becomes stiffer compared to the binary alloy. In contrast, the titanium-rich alloy exhibits a decrease in the Young’s modulus as the platinum concentration increases. While both compositions suffer from elastic instability beyond certain amount of Pt addition, the ratio between the bulk modulus to the shear modulus indicates that they both should be reasonably ductile within the elastically stable range of Pt concentrations.

Piezoelectricity, the linear relationship between stress and induced electrical charge, has attracted recent interest due to its manifestation in biological molecules such as synthetic polypeptides or amino acid crystals, including gamma (γ) glycine. It has also been demonstrated in bone, collagen, elastin and the synthetic bone mineral hydroxyapatite. Piezoelectric coefficients exhibited by these biological materials are generally low, typically in the range of 0.1-10 pm V