Concealable physical unclonable function generation and an in-memory encryption machine using vertical self-rectifying memristors.

The importance of hardware security increases significantly to protect the vast amounts of private data stored on edge devices. Physical unclonable functions (PUFs) are gaining prominence as hardware security primitives due to their ability to generate true random digital keys by exploiting the inherent randomness of the physical devices. Traditional approaches, however, require significant data movement between memory units and PUF generation circuits to perform encryption, presenting considerable energy efficiency and security challenges.

Heterogeneous reservoir computing in second-order TaO/HfO memristors.

Multiple switching modes in a TaO/HfO memristor are studied experimentally and numerically through a reservoir computing (RC) simulation to reveal the importance of nonlinearity and heterogeneity in the RC framework. Unlike most studies, where homogeneous reservoirs are used, heterogeneity is introduced by combining different behaviors of the memristor units. The chosen memristor for the reservoir units is based on a TaO/HfO bilayer, in which the conductances of the TaO and HfO layers are controlled by the oxygen vacancies and deep/shallow traps, respectively, providing both volatile and non-volatile resistive switching modes.

Application of chitosan as a natural disinfectant against porcine epidemic diarrhoea virus.

Porcine epidemic diarrhoea virus (PEDV) is one of the major pathogens causing acute enteritis, which is characterised by vomiting and watery diarrhoea and commonly leads to high rates of mortality and morbidity in suckling piglets. Chitosan has been regarded as a promising natural disinfectant. In this study, the disinfectant effect and mammalian-cell toxicity of chitosan were evaluated against PEDV using Vero cells.

Disulfide exchange assisted self-healing epoxy/PDMS/graphene oxide nanocomposites.

Vitrimers, a class of polymeric networks that change their topology above a threshold temperature, have been investigated in recent years. In order to further extend their properties, in this research, we demonstrate disulfide exchange assisted polydimethylsiloxane (PDMS)- and graphene oxide (GO)-involved epoxy vitrimers, which exhibit a reduction in glass transition temperature and storage modulus with increase in flexural strain and low-temperature self-healing. Stress relaxation and Arrhenius study were carried out for the analysis of vitrimeric behavior, where the prepared epoxy material displays self-healing at 80 °C for 5 min, whereas a low-temperature self-healing (60 °C) was observed for epoxy/PDMS/GO nanocomposites.

Gravimetric analysis of the autocatalytic growth of copper microparticles in aqueous solution.

The growth kinetics of copper microparticles was analysed by using the gravimetric method. The copper microparticles were synthesized in aqueous solution containing cupric ion and HCHO under various conditions (temperature, additive) and the total mass was monitored during the synthesis. The relation between the total mass and time was formularized using heterogeneous and pseudo-first order reaction kinetics of the autocatalytic surface growth of copper with a modification of the Finke-Watzky kinetic model.

Electrically-generated memristor based on inkjet printed silver nanoparticles.

A method to electrically induce memristor performance from inkjet-printed silver (Ag) nanoparticles is presented, which is effective on a specifically designed hourglass-shaped Ag metal device. Joule heating-induced oxidation in the bottleneck region, when applying a high current to the device, results in a metal-electrolyte-metal structure produced from just a single metal ink for the memristor operation. This electrically induced memristor shows a nonuniform dispersion of the Ag nanoparticles within the oxide electrolyte layer, depending on the bias polarity adopted during the initial metal rupture process.