Epitaxial Lift-Off of Flexible GaN‑Based HEMT Arrays with Performances Optimization by the Piezotronic Effect

High-electron-mobility transistors(HEMTs)are a promising device in the field of radio frequency and wireless communication.However,to unlock the full potential of HEMTs,the fabrication of large-size flexible HEMTs is required.Herein,a large-sized(>2 cm^(2))of AlGaN/AlN/GaN heterostructure-based HEMTs were successfully stripped from sapphire substrate to a flexible polyethylene terephthalate substrate by an electrochemical lift-off technique.The piezotronic effect was then induced to optimize the electron transport performance by modulating/tuning the physical properties of two-dimensional electron gas(2DEG)and phonons.The saturation current of the flexible HEMT is enhanced by 3.15%under the 0.547%tensile condition,and the thermal degradation of the HEMT was also obviously suppressed under compressive straining.The corresponding electrical performance changes and energy diagrams systematically illustrate the intrinsic mechanism.This work not only provides in-depth understanding of the piezotronic effect in tuning 2DEG and phonon properties in GaN HEMTs,but also demonstrates a low-cost method to optimize its electronic and thermal properties.

Relative Content of Phenoxyethanol and p-Hydroxyacetophenone in Water Phase of Oil-water Systems and Teir Relevant Control Parameters

In emulsion system, micro-organisms survive in water phase, thus concentration of preservative in water phase directly reflects to anti-fungi efficacy. As preservative easily migrates into oil phase, it reduces preservative efficacy. A common solution is to increase preservative amount in the whole system. However this way always brings safety issues as preservative is a major allergen. Another effective but safety way is to prohibit preservative migrating into oil phase. In cosmetic research area, phenoxyethanol （PE） and p-Hydroxyacetophenone （p-HAP） pair gradually emerges to be a popular preservative candidate. Thus this new preservative system has been focused as the research object in this work. The relative contents （C） of both PE （CPE） and p-HAP （Cp-HAP） in water phase has been carefully determined. Eight commonly used oils have been further employed to check CPE and Cp-HAP in different oil-water system. The other infuence parameters such as polyols, processing parameters are also investigated. Results shows squalane, petrolatum, silicone oil and hydrogenated polyisobutene might be good oil phase candidates for formulation when using PE and p-HAP preservative system. In these oil systems, PE and p-HAP are mainly located in water phase. Besides, increasing percentage of 1, 3-butylene glycol, shortening homogenization time or adding preservatives at the end of processing under lower temperature could effectively increase effective content preservatives in water phase, either.

Synthesis and modification of nanowires anchored on electrodes for electrochemical and electrophysical applications

The integration of nanowires onto electrode surfaces marks a significant advancement over traditional electrode materials,conferring upon nanowire-modified electrodes a vast array of applications within electrochemical and electrophysical domains.The nanowires used for electrode modification can be catalogized into two distinct types:anchored nanowires and free-standing nanowires.A critical advantage of anchored nanowires lies in their enhanced electrical connectivity with the substrate,which reduces electrode resistance and facilitates charge transport.Furthermore,the anchorage of nanowires onto electrodes provides additional mechanical support,bolstering the structural stability of the nanowire assembly.Here,we review the development of anchored nanowires designed for applications in energy storage,electrocatalysis,and electric field treatment(EFT)over the past decade.We focus on the synthesis and modification strategies employed for anchored nanowires,culminating in the evaluation of these fabrication and enhancement techniques.Through this analysis,we aim to furnish comprehensive insights into the preparation of anchored nanowires,guiding the selection of appropriate fabrication processes and subsequent functional modifications.

High-performance nickel metal hydride battery anode with enhanced durability and excellent low-temperature discharge capability

Current AB_(5)-type hydrogen storage alloys employed in nickel-metal hydride(NiMH)batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperature stability.To overcome these challenges,we introduce a hydrothermal synthesized LaF_(3)coating layer on the surface of the AB_(5)anode material.This LaF_(3)coating layer adds a protective barrier for the active material,significantly improving the battery's cycle life and high-temperature stability.Our findings indicate that(1)the LaF_(3)coated anode demonstrates an extended cycle life with increased specific capacity and a capacity retention of 88%after 40 cycles of abusive overcharging and rapid discharging at room temperature.(2)The synthesized anode exhibits a 97%recovery of its specific capacity of 292.7 mAh/g following 144 h of high-temperature storage.(3)The low-temperature discharge capacity of the synthesized anode remains on par with the pristine AB_(5)alloy at 230.4 mAh/g in a-40℃environment.This research presents a significant advancement in hydrogen storage alloy coatings and offers valuable insights for designing electrodes in NiMH batteries.

Stretchable and durable HD-sEMG electrodes for accurate recognition of swallowing activities on complex epidermal surfaces

Surface electromyography(sEMG)is widely used in monitoring human health.Nonetheless,it is challenging to capture high-fidelity sEMG recordings in regions with intricate curved surfaces such as the larynx,because regular sEMG electrodes have stiff structures.In this study,we developed a stretchable,high-density sEMG electrode array via layerby-layer printing and lamination.The electrode offered a series of excellent human‒machine interface features,including conformal adhesion to the skin,high electron-to-ion conductivity(and thus lower contact impedance),prolonged environmental adaptability to resist water evaporation,and epidermal biocompatibility.This made the electrode more appropriate than commercial electrodes for long-term wearable,high-fidelity sEMG recording devices at complicated skin interfaces.Systematic in vivo studies were used to investigate its ability to classify swallowing activities,which was accomplished with high accuracy by decoding the sEMG signals from the chin via integration with an ear-mounted wearable system and machine learning algorithms.The results demonstrated the clinical feasibility of the system for noninvasive and comfortable recognition of swallowing motions for comfortable dysphagia rehabilitation.

Direct LED writing of submicron resist patterns： Towards the fabrication of individually-addressable InGaN sub-micron stripe-shaped LED arrays

Submicron stripe-shaped InGaN light-emitting diode （LED） arrays with individually addressable capabilities are demonstrated. The critical submicron- stripe metallic electrodes, which define the emission pattern, are formed by direct LED writing in a mask-free manner. The individually addressable submicron-stripe LEDs show excellent performance in terms of their electrical characteristics （with typical turn-on voltage of 3 V, operational stability and power output up to 28 ~W at 3 mA）. Unlike conventional broad-sized LEDs, the efficiency droop of the submicron-stripe LED is significantly suppressed--in fact, there is no efficiency droop for current densities up to 100 A/cm^2. Furthermore, the submicron-stripe LED shows a lower temperature-dependent shift of the emission wavelength. The lateral emission width is increased with increasing injection current, resulting in a wider lateral emission size than the metallic submicron-stripe electrode. The underlying physics of these phenomena are analysed. Such submicron-stripe LED arrays open up promising applications in nanophotonics and bio-sensing.

Liver transplantation for hepatitis B virus-related cirrhosis with acute-on-chronic liver failure and grade 3-4 hepatic encephalopathy:Survival and quality of life

To the Editor:Twenty-eight-day mortality rates in patients with acute-on-chronic liver failure(ACLF)grades 1,2,and 3,as per the European Association for the Study of the Liver-Chronic Liver Failure(EASL-CLIF)classification,are 22%,32%,and 73%,respectively.[1]The 30-day mortality rates in cirrhosis with grade 3-4 hepatic encephalopathy(HE)and≥2 extra-hepatic organ failures(OFs),and one OF are 70%and 44%,respectively.[2]It suggests that the prognosis in cirrhotic patients with ACLF and grades 3-4 HE is usually poor,which can be effectively treated by liver transplantation(LT)with good post-LT survival rates.[3,4]Hepatitis B virus(HBV)is the main cirrhotic etiology in China.[5]Currently,there is limited data available regarding LT for HBV-related ACLF patients with grade 3-4 HE(hereinafter referred to as ACLF with grade 3-4 HE).This study aimed to investigate the peri-LT complications,pre-LT prognostic scorings,survival,and quality of life assessed by the Karnofsky performance status(KPS)scores at post-LT 1 year in ACLF with grade 3-4 HE,when compared with other three transplanted groups(ACLF with grade 1-2 HE,ACLF with no HE,and cirrhosis with no ACLF and HE).