Future Electronics Research Articles

Anisotropic electron transport Rashba effects in valleytronics

Electrically induced space separation of free carriers from different valleys in bulk multivalley semiconductors in restricted geometry was first reported by E. I. Rashba in 1965. This Rashba valley-dependent size effect envisioned the use of a valley index in future electronics. It remains relevant at present for the rapidly developing field of valleytronics. The authors show that electrically induced valley-polarized domains can arise in two-dimensional multivalley semiconductor nanosystems with anisotropic valleys ($n$-Si, $n$-AlAs, etc.). The formation of such domains leads to space separation of carriers from different valleys, generates valley currents, and induces electric (magnetic) fields.

First-principles study on the electronic structures and topological properties of Bi(110)/IV-VI and Bi(110)/V-V van der Waals heterostructures

Based on the first-principles calculations, numerous theoretical research efforts have been made to exploit electronic structures and topological properties in Bi(110) and IV-VI groups (Sn0.5Se0.5, Sn0.5Se0.25Te0.25, Sn0.5Te0.5), V-V groups (Sb0.5As0.5, Bi0.5As0.5, α-Bi0.5Sb0.5, α2-Bi0.5Sb0.5) substrates heterostructures. Molecular dynamics confirmed that the proposed bilayer heterostructures are stable. The electronic analysis results show that the valence and conduction bands near the Fermi level are mainly contributed by Bi(110). More importantly, Bi(110)/Sn0.5Te0.5 and Bi(110)/Sn0.5Se0.25Te0.25 have non-topological properties. However, when applying 20% biaxial tensile strain, both of them have nontrivial Z2 topological invariants and topological edge states. Our findings not only breathe new power into the family of 2D materials but also highlight these 2D semiconductors as attractive materials potential for future electronics and topological devices.

Synthesis of conducting water-dispersible polyaniline particles and its template-guided patterning

Organic conductors are a promising material for future electronics. Although, its processing is a big challenge. In this manuscript, we demonstrate micropatterning of polyaniline within the pores of a polycarbonate membrane to fabricate a device for a conductometric sensor. The aqueous dispersion of polyaniline particles was prepared by single pot oxidative polymerization of aniline monomer using dodecylbenzene sulfonic acid as a surfactant as well as a dopant, and the polyaniline from its aqueous dispersion was then precipitated within the pores of polycarbonate membrane by adding solvents of varying polarities. The phase diagram of precipitation was drawn by titrating the polyaniline dispersion with tetrahydrofuran solvent. The dispersion was characterized by Fourier transform infrared spectroscopy and UV-Vis spectroscopy, as well as a transmission electron microscope. The molecular weight of the synthesized polyaniline was measured by gel permission chromatography. The morphology of polyaniline has been compared through transmission electron microscopy in its dispersed form and after precipitation. Field emission scanning electron microscopy was used to see the growth of channel formation of precipitated polyaniline within the pores of the polycarbonate membrane. The electroactivity of the precipitated polyaniline was measured by in-situ conductance measurement as a function of the electrochemical state.

Ultrafast, autonomous self-healable iontronic skin exhibiting piezo-ionic dynamics

The self-healing properties and ionic sensing capabilities of the human skin offer inspiring groundwork for the designs of stretchable iontronic skins. However, from electronic to ionic mechanosensitive skins, simultaneously achieving autonomously superior self-healing properties, superior elasticity, and effective control of ion dynamics in a homogeneous system is rarely feasible. Here, we report a Cl-functionalized iontronic pressure sensitive material (CLiPS), designed via the introduction of Cl-functionalized groups into a polyurethane matrix, which realizes an ultrafast, autonomous self-healing speed (4.3 µm/min), high self-healing efficiency (91% within 60 min), and mechanosensitive piezo-ionic dynamics. This strategy promotes both an excellent elastic recovery (100%) and effective control of ion dynamics because the Cl groups trap the ions in the system via ion-dipole interactions, resulting in excellent pressure sensitivity (7.36 kPa−1) for tactile sensors. The skin-like sensor responds to pressure variations, demonstrating its potential for touch modulation in future wearable electronics and human–machine interfaces.

Highly surface-conformable thermoelectric patches for efficient thermal contact with arbitrary substrates

Organic thermoelectric (TE) materials are attractive for application as the main or auxiliary power sources of portable and wearable electronic devices. Although utilizing waste heat from practical heat sources (including the human body) remains challenging, this can be solved by developing surface-conformable and body-attachable TE materials. This study introduces a method for preparing multifunctional TE patches to facilitate efficient thermal contact formation between TE patches and various heat sources with flat, curved, wavy, wrinkled, or microstructured surfaces and different textures. The TE patches are prepared using a mixed solution comprising few-walled carbon nanotubes, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), and a commercial gel polymer blend to form freestanding hydrogel nanocomposite films. Under optimized conditions, the composite films exhibit good mechanical (bending and healing) and TE properties and excellent environmental long-term stability. Because the films can form superior thermal contact with arbitrary surfaces, energy can be harvested more efficiently using the conformable TE patches than using the nonconformable patches, suggesting that the potential application range of organic TE materials for future self-powered wearable electronics is not limited to energy harvesting but can be extended to precise temperature sensing.

Destructive-Treatment-Free Rapid Polymer-Assisted Metal Deposition for Versatile Electronic Textiles.

Highly conductive, durable, and breathable metal-coated textiles are critical building block materials for future wearable electronics. In order to enhance the metal adhesion on the textile surface, existing solution-based approaches to preparing these materials require time-consuming presynthesis and/or premodification processes, typically in the order of tens of minutes to hours, on textiles prior to metal plating. Herein, we report a UV-induced rapid polymer-assisted metal deposition (r-PAMD) that offers a destructive-treatment-free process to deposit highly conductive metals on a wide variety of textile materials, including cotton, polyester, nylon, Kevlar, glass fiber, and carbon cloth. In comparison to the state of the arts, r-PAMD significantly shortens the modification time to several minutes and is compatible with the roll-to-roll fabrication manner. Moreover, the deposited metals show outstanding adhesion, which withstands rigorous flexing, abrasion, and machine washing tests. We demonstrate that these metal-coated textiles are suitable for applications in two vastly different fields, being wearable and washable sensors, and lithium batteries.

Eco-Friendly Keratin-Based Additives in the Polymer Matrix to Enhance the Output of Triboelectric Nanogenerators.

A triboelectric nanogenerator (TENG) is an energy generator that converts mechanical energy into electrical energy using triboelectricity at a nanoscale. Given their potential application as power sources in electronic devices, various attempts have been made to improve their output performance. Here, we present an eco-friendly, low-cost, and facile fabrication method to enhance TENG characteristics with keratin protein additives. Keratin sources, human and cat hair, are processed into powder and added to the friction layer, which increases their positive charge affinity, thereby boosting the output performance of the TENG. The output performances of the keratin-added TENG (K-TENG) are measured in the vertical contact-separation mode, with both additives having the highest output values at 5 wt % load. The K-TENG generates more output voltage and current values than the pristine TENG by 90 and 208%, respectively. Hence, we conclude that this method would potentially promote TENG as a strong candidate for a competitive "green" energy harvesting device in future electronics applications.

A bioinspired flexible neuromuscular system based thermal-annealing-free perovskite with passivation

Brain-inspired electronics require artificial synapses that have ultra-low energy consumption, high operating speed, and stable flexibility. Here, we demonstrate a flexible artificial synapse that uses a rapidly crystallized perovskite layer at room temperature. The device achieves a series of synaptic functions, including logical operations, temporal and spatial rules, and associative learning. Passivation using phenethyl-ammonium iodide eliminated defects and charge traps to reduce the energy consumption to 13.5 aJ per synaptic event, which is the world record for two-terminal artificial synapses. At this ultralow energy consumption, the device achieves ultrafast response frequency of up to 4.17 MHz; which is orders of magnitude magnitudes higher than previous perovskite artificial synapses. A multi-stimulus accumulative artificial neuromuscular system was then fabricated using the perovskite synapse as a key processing unit to control electrochemical artificial muscles, and realized muscular-fatigue warning. This artificial synapse will have applications in future bio-inspired electronics and neurorobots.

As Good as Gold

Gold may hold the key to unlocking reaction pathway for future electronics

Bounds on anomalous quartic WWZγ couplings in e – p collisions at the FCC-he

Non-Abelian structure of the standard model (SM) predicts the self-interactions of gauge bosons triple gauge couplings (TGC) and quartic gauge couplings (QGC). On the other hand, it is also important to determine the deviations from SM via anomalous triple gauge couplings and anomalous quartic gauge couplings (aQGC) to test the nature of the SM and to see the effects of new physics arising from the beyond the standard model. In this study, we focus on the e − p → jZ γ ν e → j(l + l −)γ ν e process to examine the WWZ γ aQGC at the Future Circular Collider-hadron electron with center-of-mass energy TeV using a model-independent way in the effective theory approach. A Cut-based method is applied to analyse the signal and relevant SM background. Using the total cross-sections, we constrained the anomalous f T,i=0,1,2,5,6,7/Λ4 couplings arising from dimension-8 operators at 95% confidence level for the dilepton decay of the Z-boson. The results are composed of integrated luminosities of and 3 ab −1 under the systematic uncertainties of 0%, 5% and 10%. In the calculations, we use the form factor to eliminate the effects of the violation of unitarity. With this, we obtained the limits for the energy scale of the form factor Λ = 1 TeV. In addition to all this, we use the advantages of ep collisions for analysing the process with much cleaner environment and lower background effects compared with the pp collisions. The obtained sensitivities on f T, i=0, 1, 2, 5, 6, 7/Λ4 are comparable with the experimental results and related phenomenological studies in the literature.

Deformable lithium-ion batteries for wearable and implantable electronics

Deformable lithium-ion batteries (LIBs) have attracted increasingly widespread attention due to their enormous prospects for powering flexible electronics. In recent years, technological advances in manufacturing deformable LIBs at the material and device levels have promoted the rapid and sustainable development in energy storage. Despite recent advances, there is so far no review to make a comprehensive introduction focusing on the topic of deformable LIBs for future wearable and implantable electronics. This review systematically summarizes the recent progresses in deformable LIBs and their applications in various scenarios. Specifically, we classify the deformable LIBs into several categories such as stretchable LIBs, self-healing LIBs, shape memory LIBs, biodegradable LIBs, etc. Initially, the fundamentals of LIBs, such as their components and working mechanism, are introduced. Then, various strategies for constructing deformable LIBs are discussed in detail, with a particular focus on stretchable LIBs. Subsequently, the latest advances in the application of deformable LIBs in wearable/implantable electronic systems are summarized. To finalize, the challenges and prospects are outlined to promote further development in this booming field. This review has the potential to inspire researchers working on the development of high-performance deformable energy storage devices and to contribute to the future development of flexible electronics.

Synthesis, structural, optical and electrical characterization of Y2O3/poly(ethylene glycol)–poly(vinyl chloride) based nanocomposite solid polymer electrolytes

AbstractNanocomposite solid polymer electrolytes (NCSPEs) have attracted a lot of attention as excellent candidates for future electronics, photonics and energy storage devices. In this work, Y2O3 (YO) nanosheets were prepared by a free‐template sol–gel method and incorporated inside a poly(ethylene glycol)–poly(vinyl chloride) (blend) matrix via solution casting. NCSPE films were then prepared by adding NaClO4 (NC) or LiCl (LC) to the nanocomposite solutions. XRD and field emission SEM showed that YO has a body‐centered cubic structure and a crystallite size of 24.8 nm, and looks like nanosheets with a high purity. The XRD results of the films showed that YO loading and salt complexation increase the films' amorphous structure. SEM was used to study the surface morphology and film thickness. Fourier transform infrared spectra confirmed the complexation and interactions between the YO/blend and NC or LC. UV–visible spectroscopy revealed that the films display low transmittance (˂17%), an extinction coefficient k between 0.2 × 10−3 and 1 × 10−3 and a comparatively high refractive index. The band gap of the blend decreased from 4.3 to 4.0 eV on loading YO, and NC exhibited a higher impact on Eg compared with LC. A significant increase in with complexing was reported and the maximum value was 7.4 × 10−4 S cm−1 for the 10 wt% NC/YO/blend structure. The NCSPE films are ionic conductors and have a non‐Debye type of conductivity relaxation, and the applied AC conduction mechanism is correlated barrier hopping. © 2022 Society of Industrial Chemistry.

Discovery potential for split supersymmetry with thermal dark matter

Supersymmetric extensions of the Standard Model with scalar superpartners above 10 TeV are well motivated since the Higgs boson mass can be explained by quantum corrections while maintaining gauge coupling unification. If supersymmetry breaking is transmitted to gauginos via anomaly mediation, the gaugino masses are loop suppressed compared to scalar masses, and the lightest supersymmetric particle is the Higgsino or wino, which can be the dark matter. In this setup, we identify the regions of parameter space that reproduce the observed Higgs boson mass and the thermal abundance of dark matter. We analyze the effects of complex phases in the gaugino mass parameters on the electron electric dipole moment (EDM) and the dark matter scattering cross section. We find that, for scalar masses up to 10 PeV and any size of the complex phases, the model with Higgsino dark matter is within reach of planned experiments -- Advanced ACME via electron EDM and LUX-ZEPLIN via dark matter direct detection -- with complementary discovery potentials, and the model with wino dark matter is within reach of future electron EDM experiments.

Employment of nanodiamond photocathodes on MPGD-based HEP detector at the future EIC

In high momenta range, the construction of a Ring Imaging CHerenkov (RICH) detector for the particle identification at the future Electron Ion Collider (EIC) is a complicated task. A compact collider setup imposes to construct a RICH with a short radiator length, hence limiting the number of photons. The number of photons can be increase by choosing to work in far UV region. However, as standard fused-silica windows are opaque below 165 nm, therefore, a windowless RICH approach could be a possible choice. In the far UV range, CsI is a widely used photo-cathode (PC) to detect photons, but because of its hygroscopic nature, it is very delicate to handle. Its Quantum Efficiency (QE) degrades in high intensity ion fluxes. These are the key reasons to search a novel, less delicate PC with sensitivity in the far UV region. Hydrogenated nanodiamond films are proposed as an alternative PC material and shown to have promising characteristics. The performance of nanodiamond PC coupled to THGEM-based detectors is the objects of our ongoing R & D.The first phase of these studies includes the characterization of THGEMs coated with nanodiamont PC, the comparison of the effective QE in vacuum and in gaseous atmospheres, the hardness respect to the PC bombardment by ions from the multiplication process. The approach is described in detail as well as all the results obtained so far with these exploratory studies.

Newly Synthesized High‐k Polymeric Dielectrics with Cyclic Carbonate Functionality for Highly Stability Organic Field‐Effect Transistor Applications

AbstractOrganic field‐effect transistors (OFETs) with low‐voltage‐operating high‐stability are regarded as one of the key components of future electronics. However, it remains a challenge to enhance bias–stress stability, mechanical durability and environmental adaptability while reducing the operating voltage of the flexible OFETs. In this study, a new strategy of introducing high‐dipole‐moment groups into polymer side chains to enhance the intensity of polarization was proposed. This strategy can redirect cyclic carbonate side chains of high‐dipole groups under the action of electric fields and realize stable operation and efficient charge transfer. The experiments showed that high‐performance flexible OFETs were mainly attributed to the synthesized polymers through molecular structure designing which not only have high dielectric constant (k > 5) and high electrical insulating property but also favor the growth of organic semiconductor films. The flexible OFETs still showed excellent mechanical flexibility, high electrical, thermal and humidity stability. In addition, highly OFETs were applied into a floating‐gate memory with fullerene (C60) embedded charge memory layer and an integrated one‐transistor‐one‐transistor memory cell. They exhibited excellent memory performance with a large memory window (8.5 V), current ratio (103), stable retention (2 × 104 s), cyclic endurance (200 cycles), multi‐level memory (over 4 levels) and non‐destructivity.

An integrated wearable self-powered platform for real-time and continuous temperature monitoring

Biocompatible and reliable temperature monitoring platforms are constantly required to develop wearable electronics for future sophisticated health diagnosis and protection of high-risk individuals. Considering the fact that heat exposures during pregnancy might increase the risk for abortions, premature birth or congenital heart defects, here, we propose a conceptual self-powered temperature monitoring platform for simultaneous real-time tracking of the temperature variation in lower limb of a pregnancy woman and her surrounding environment during exercise. Thanks to the special channel design and local spindle-shaped construction, the single yarn-based temperature (SYBT) sensor exhibits ultrahigh sensitivity, bending resistance, good biocompatibility and integrability with fabrics. A vertical contact-separate mode triboelectric nanogenerator embedded into a shoe extracts energy from body motion to power the SYBT sensors, achieving the self-powered features of the platform. Coupled with wirelessly date transmitting and user interfaces, the temperatures of pregnant volunteer’s lower limb and surrounding ambience are simultaneously and continuously monitored during exercise in a self-powered manner. Such SYBT sensors and self-powered design strategy provides a new avenue for future temperature monitoring electronics.

A new TCAD simulation method for direct CMOS electron detectors optimization

A custom CMOS image sensor hardened by design is characterized in a transmission electron microscope, with the aim to extract basic parameters such as the quantum efficiency, the modulation transfer function and finally the detective quantum efficiency. In parallel, a new methodology based on the combination of Monte Carlo simulation of electron distributions and TCAD simulations is proposed and performed on the same detector, and for the first time the basic parameters of a direct CMOS electron detector are extracted thanks to the TCAD. The methodology is validated by means of the comparison between experimental and simulation results. This simulation method may be used for the development of future electron detectors.

Advances in Flexible Organic Photodetectors: Materials and Applications.

Future electronics will need to be mechanically flexible and stretchable in order to enable the development of lightweight and conformal applications. In contrast, photodetectors, an integral component of electronic devices, remain rigid, which prevents their integration into everyday life applications. In recent years, significant efforts have been made to overcome the limitations of conventional rigid photodetectors, particularly their low mechanical deformability. One of the most promising routes toward facilitating the fabrication of flexible photodetectors is to replace conventional optoelectronic materials with nanomaterials or organic materials that are intrinsically flexible. Compared with other functional materials, organic polymers and molecules have attracted more attention for photodetection applications due to their excellent photodetection performance, cost-effective solution-fabrication capability, flexible design, and adaptable manufacturing processes. This article comprehensively discusses recent advances in flexible organic photodetectors in terms of optoelectronic, mechanical properties, and hybridization with other material classes. Furthermore, flexible organic photodetector applications in health-monitoring sensors, X-ray detection, and imager devices have been surveyed.

A κ-Carrageenan-Containing Organohydrogel with Adjustable Transmittance for an Antifreezing, Nondrying, and Solvent-Resistant Strain Sensor.

Gel polymers are widely used in different fields due to their unique properties, especially in flexible electronic devices. However, developing multienvironmentally-tolerant (antifreezing, antidrying, and solvent-resistant) gel polymer-based soft electronics is still a significant challenge. Herein, a binary solvent system-based versatile organohydrogel is designed and successfully prepared, which exhibits superior stretchability, favorable self-adhesive properties, prominent temperature tolerance, and excellent solvent-resistant capabilities. Furthermore, the as-assembled organohydrogel-based sensor demonstrates a satisfied sensitivity (GF = 1.8), wide strain range (5-500%), and outstanding human motion detection. Meanwhile, the obtained organohydrogel can also serve as an all-weather sensor for achieving precise and reliable mechanical sensing in a wide temperature range from -50 to 50 °C and diverse liquid media consisting of water, toluene, and carbon tetrachloride. Interestingly, the organohydrogel displays a repeatable transmittance change behavior in water and dimethyl sulfoxide, based on this feature, which could realize the functional applications for recording and erasing information. It is envisioned that these superior performances render the as-prepared organohydrogel suitable to develop future advanced soft electronics with multienvironmental tolerance.

Direct Freeform Laser Fabrication of 3D Conformable Electronics

Abstract3D conformable electronic devices on freeform surfaces show superior performance to the conventional, planar ones. They represent a trend of future electronics and have witnessed exponential growth in various applications. However, their potential is largely limited by a lack of sophisticated fabrication techniques. To tackle this challenge, a new direct freeform laser (DFL) fabrication method enabled by a 5‐axis laser processing platform for directly fabricating 3D conformable electronics on targeted arbitrary surfaces is reported. Accordingly, representative laser‐induced graphene (LIG), metals, and metal oxides are successfully fabricated as high‐performance sensing and electrode materials from different material precursors on various types of substrates for applications in temperature/light/gas sensing, energy storage, and printed circuit board for circuit. Last but not the least, to demonstrate an application in smart homes, LIG‐based conformable strain sensors are fabricated and distributed in designated locations of an artificial tree. The distributed sensors have the capability of monitoring the wind speed and direction with the assistance of well‐trained machine‐learning models. This novel process will pave a new and general route to fabricating 3D conformable electronic devices, thus creating new opportunities in robotics, biomedical sensing, structural health, environmental monitoring, and Internet of Things applications.