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Abstract Physical unclonable functions (PUFs) are of immense potential in authentication scenarios for Internet of Things (IoT) devices. For creditable and lightweight PUF applications, key attributes, including low power, high reconfigurability and large challenge-response pair (CRP) space, are desirable. Here, we report a ferroelectric field-effect transistor (FeFET)-based strong PUF with high reconfigurability and low power, which leverages the FeFET cycle-to-cycle variation throughout the workflow and introduces charge-domain in-memory computing. The proposed PUF cells are fabricated at 28 nm node, and the experimental measurements reveal high uniformity, uniqueness and repeatability. Remarkably, our PUF achieves near-ideal reconfigurability and ultra-low 1.89fJ per bit readout energy, significantly outperforming the state-of-the-art PUFs. Furthermore, we show that the PUF is robust against parameter variations and resilient to machine learning (ML) attacks. These performances highlight the great promise of the FeFET-based strong PUF as a feasible IoT security solution.

The interpenetrating connection of icosahedra network (ICOIN) was termed as structural skeleton, which could quantify the strength and ductility of MGs. The impact of different rejuvenation methods on medium-range order (MRO) alterations was rarely studied. This work employed molecular dynamics simulations to examine the difference in MRO evolution of metallic glasses treated by recovery annealing and thermal-pressure treatment during uniaxial tension. All of the specimens obtain enhanced ductility due to improved potential energy. During tension, ICOI of all rejuvenated specimens exhibits an increased destruction rate and a decreased transformation rate. However, there are some converse characteristics in the specimens under different rejuvenation methods. The rejuvenated specimens treated by recovery annealing exhibit increased free volume and decreased ICOIN density. After thermal-pressure treatment, the rejuvenated specimens demonstrated decreased free volume and enhanced ICOIN density. During tension, the enhancement of icosahedral free volume in specimens treated by thermal pressure largely decreased the ICOIN density, thereby increasing the ductility. After tension, the rejuvenated specimens under high pressure have a significant reduction in ICOIN density compared to those under recovery annealing. The significance of this work is to accurately regulate the ICOIN density of rejuvenated specimens.

Abstract Manipulating surface charge, electric field, and plasma afterglow in a non-equilibrium plasma is critical to control plasma-surface interaction for plasma catalysis and manufacturing. Here, we show enhancements of surface charge, electric field during breakdown, and afterglow by ferroelectric barrier discharge. The results show that the ferroelectrics manifest spontaneous electric polarization to increase the surface charge by two orders of magnitude compared to discharge with an alumina barrier. Time-resolved in-situ electric field measurements reveal that the fast polarization of ferroelectrics enhances the electric field during the breakdown in streamer discharge and doubles the electric field compared to the dielectric barrier discharge. Moreover, due to the existence of surface charge, the ferroelectric electrode extends the afterglow time and makes discharge sustained longer when alternating the external electric field polarity. The present results show that ferroelectric barrier discharge offers a promising technique to tune plasma properties for efficient plasma catalysis and electrified manufacturing.

Personal healthcare monitoring is a promising field, as continuous, individual-specific, real-time health information can enable better care and more precise diagnoses. One barrier to continuous monitoring lies in the power requirements and data retrieval needed for on-body sensors, as well as the need for measurements in different locations on the body. Ideally, these sensors would be self-powered, unobtrusive, and compatible with low-power communication systems. However, existing wireless self-powered on-body sensors are often limited by energy constraints, making real-time data transfer challenging with conventional Bluetooth communications. In this work, we present a wearable, self-powered on-body sensor system that utilizes an ultra-low-power backscatter radio scheme to enable real-time wireless communication, powered by sweat batteries, thus eliminating the need for external power. We demonstrate the capabilities of this system with a continuous, real-time electrocardiogram (ECG) system that transmits data to a cell phone held by the user.

In recent years, boundary layer flame flashback (BLF) has re-emerged as a technological and operational issue due to the more widespread use of alternative fuels as a part of a global effort to promote carbon neutrality. While much understanding has been achieved in experiments and simulations of BLF in the past decades, the theoretical modeling of BLF still largely relies on the progress made as early as the 1940s, when the critical gradient model (CGM) for the laminar flame flashback was proposed by Lewis and von Elbe. The CGM does not account for the modification of the upstream flow by the flame, which has been recently shown to play a role in BLF. The aim of the present work is to gain additional insight into the effects of thermal gas expansion and confinement on the flame-flow interaction in laminar BLF. Two-dimensional simulations of the confined laminar BLF in a channel are performed in this work. The parametric study focuses on the channel width, the thermal gas expansion coefficient, and the heat losses to the wall. This study evaluates the influence of these factors on the critical condition for the flame flashback. By varying the channel width, it is demonstrated that at the critical condition, the incoming flow in narrow channels is modified globally by the thermal gas expansion, while in wider channels, the flow modification by the flame tends to be more local. In narrow channels, a non-monotonic dependence of the critical-condition centerline velocity on the channel width has been identified. The variation of the heat loss to the wall confirms that the wall’s thermal conditions can significantly alter the flashback limit, with the flashback propensity being larger when the thermal resistance of the wall is high. To assess the general applicability of the CGM, the flame consumption speed and the flow velocity near the wall are quantified. The results confirm that the assumption of flame having no influence on the upstream flow, employed in the CGM, is not fulfilled under confinement for a realistic thermal gas expansion. This results in a general disagreement between the simulations and the CGM, which implies that the thermal expansion effects should be accounted for when considering the confined boundary layer flashback limits. It is shown that the critical velocity gradient increases with the gas expansion coefficient for the given channel width and wall thermal condition.

Abstract 1. Global interest in building healthy soils combined with new DNA sequencing technologies has led to the generation of a vast amount of soil microbial community (SMC) data. 2. SMC analysis is being adopted widely for monitoring ecological restoration trajectories. However, despite the large and growing quantity of soil microbial data, it remains unclear how these data inform and best guide restoration practice. 3. Here, we examine assumptions around SMC as a tool for guiding ecosystem restoration and evaluate the effectiveness of using species inventories of SMC as a benchmark for restoration success. 4. We investigate other approaches of assessing soil health, and conclude that we can significantly enhance the utility of species inventory data for ecological restoration by complementing it with the use of non‐molecular approaches.

Abstract 1. Multiple drivers of environmental change pose a significant challenge for ecological restoration, including climate change, soil salinization and environmental pollution. Due to the important role that soil biota play in enabling plants to cope with a variety of abiotic stressors, there is growing interest in the use of microbial inoculations to facilitate native plant restoration in the face of such change. 2. Recently, novel methods have begun being explored in agriculture to harness stress‐conditioned soil biota for improving abiotic stress tolerance in crop species. Similar applications in ecological restoration – where plants are inoculated with indigenous soil microbial communities that are preconditioned to various abiotic stressors – could potentially increase our capacity to restore degraded ecosystems under global change. 3. In this paper, we aim to (1) outline the ways in which soil microbial communities might be conditioned in order to confer greater stress tolerance to plants that are targets for restoration; (2) highlight successful (and unsuccessful) examples where stress‐tolerant soil microbial communities were utilized to improve plant performance; (3) describe the ways in which stress‐conditioned soil biota could be deployed in order to assist ecological restoration; and (4) discuss the potential risks and outstanding questions associated with such an approach. 4. If restoration practitioners are able to harness the soil microbiome to improve plant stress tolerance as is currently being explored in agriculture, this could revolutionize methods for the restoration of degraded lands in the Anthropocene.

Photoacoustic tomography is a technique to reconstruct the image of light energy absorption distribution in tissues based on the detected photoacoustic signals. In recent years, this research field has been greatly developed, and its application range is wide, including anatomy, functionality, and molecular imaging. However, the conversion efficiency of photoacoustic effect from light to sound is quite low, which leads to the low signal-to-noise ratio of photoacoustic signal and the poor quality of reconstructed photoacoustic image. The traditional method to improve the signal-to-noise ratio of photoacoustic signals is data averaging method, but it seriously limits the imaging speed due to multiple acquisition. Without sacrificing signal fidelity and imaging speed, an empirical mode decomposition (EMD) combined with conditional mutual information de-noising algorithm for photoacoustic tomography is proposed in this paper. The simulation results and experimental results of photoacoustic signal de-noising achieve significant improvement of signal-to-noise ratio of photoacoustic signal and the enhancement of contrast of the reconstructed image. The simulation results and experimental results show that EMD combined with mutual information method improves at least 2 dB and 3 dB, respectively, more than traditional wavelet threshold method and band-pass filter. The improvement of contrast-to-noise ratio is more than 2 dB and 3 dB, respectively, more than traditional wavelet threshold method and band-pass filter.

Photoacoustic tomography (PAT), a promising medical imaging method that combines optical and ultrasound techniques, has been developing for decades mostly in preclinical application. A recent trend is to utilize the economical laser source to develop a low-cost sensing and imaging system, which aims at an affordable solution in clinical application. These low-cost laser sources have different modulation modes such as pulsed modulation, continuous modulation and coded modulation to generate different profiles of PA signals in photoacoustic (PA) imaging. In this paper, we review the recent development of the photoacoustic sensing and imaging based on the economical laser sources such as laser diode (LD) and light-emitting diode (LED) in different kinds of modulation types, and discuss several representative methods to improve the performance of such imaging systems based on low-cost laser sources. Finally, some perspectives regarding the future development of portable PAT systems are discussed, followed by the conclusion.

Manipulating surface charge, electric field, and plasma afterglow in a non-equilibrium plasma is critical to control plasma-surface interaction for plasma catalysis and manufacturing. Here, we show enhancements of surface charge, electric field during breakdown, and afterglow by ferroelectric barrier discharge. The results show that the ferroelectrics manifest spontaneous electric polarization to increase the surface charge by two orders of magnitude compared to discharge with an alumina barrier. Time-resolved in-situ electric field measurements reveal that the fast polarization of ferroelectrics enhances the electric field during the breakdown in streamer discharge and doubles the electric field compared to the dielectric barrier discharge. Moreover, due to the existence of surface charge, the ferroelectric electrode extends the after-glow time and makes discharge sustained longer when alternating the external electric field polarity. The present results show that ferroelectric barrier discharge offers a promising technique to tune plasma properties for efficient plasma catalysis and electrified manufacturing. [ABSTRACT FROM AUTHOR]