Control devices incorporated with shape memory alloy

Abstract： Shape Memory Alloy （SMA） is a type of material that offers some unique characteristics for use in devices for vibration control applications. Based on SMA＇s material properties, fottr types of control devices that incorporate NiTi SMA wires are introduced in this paper, which include three types of dampers （SMA damper, SMA-MR damper and SMA-friction damper） and one kind of isolation bearing （SMA-rubber bearing）. Mechanical models of these devices and their experimental verifications are presented. To investigate the control performance of these devices, the SMA-MR damper and SMA-rubber bearing are applied to structures. The results show that the control devices could be effective in reducing the seismic response of structures.

Observation of Resistive Switching Memory by Reducing Device Size in a New Cr/CrO_x/TiO_x/TiN Structure

The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confirmed a viahole size of 0.4 lm.A 3-nm-thick amorphous Ti Oxwith 4-nm-thick polycrystalline Cr Oxlayer was observed.A small 0.4-lm device shows reversible resistive switching at a current compliance of 300 l A as compared to other larger size devices(1–8 lm)owing to reduction of leakage current through the Ti Oxlayer.Good device-to-device uniformity with a yield of[85%has been clarified by weibull distribution owing to higher slope/shape factor.The switching mechanism is based on oxygen vacancy migration from the Cr Oxlayer and filament formation/rupture in the Ti Oxlayer.Long read pulse endurance of[105cycles,good data retention of 6 h,and a program/erase speed of 1 ls pulse width have been obtained.

Ultrafast reconfigurable direct charge trapping devices based on few-layer MoS_(2)

Charge trapping devices incorporating 2D materials and high-κdielectrics have emerged as promising candidates for compact,multifunctional memory devices compatible with silicon-based manufacturing processes.However,traditional charge trapping devices encounter bottlenecks including complex device structure and low operation speed.Here,we demonstrate an ultrafast reconfigurable direct charge trapping device utilizing only a 30 nm-thick Al_(2)O_(3)trapping layer with a MoS_(2)channel,where charge traps reside within the Al_(2)O_(3)bulk confirmed by transfer curves with different gatevoltage sweeping rates and photoluminescence(PL)spectra.The direct charging tapping device shows exceptional memory performance in both three-terminal and two-terminal operation modes characterized by ultrafast three-terminal operation speed(~300 ns),an extremely low OFF current of 10^(-14)A,a high ON/OFF current ratio of up to 10^(7),and stable retention and endurance properties.Furthermore,the device with a simple symmetrical structure exhibits VDpolarity-dependent reverse rectification behavior in the high resistance state(HRS),with a rectification ratio of 10^(5).Additionally,utilizing the synergistic modulation of the conductance of the MoS_(2)channel by V_(D)and V_(G),it achieves gate-tunable reverse rectifier and ternary logic capabilities.

Investigation of flux dependent sensitivity on single event effect in memory devices

Heavy-ion flux is an important experimental parameter in the ground based single event tests. The flux impact on a single event effect in different memory devices is analyzed by using GEANT4 and TCAD simulation methods. The transient radial track profile depends not only on the linear energy transfer （LET） of the incident ion, but also on the mass and energy of the ion. For the ions with the energies at the Bragg peaks, the radial charge distribution is wider when the ion LET is larger. The results extracted from the GEANT4 and TCAD simulations, together with detailed analysis of the device structure, are presented to demonstrate phenomena observed in the flux related experiment. The analysis shows that the flux effect conclusions drawn from the experiment are intrinsically connected and all indicate the mechanism that the flux effect stems from multiple ion-induced pulses functioning together and relies exquisitely on the specific response of the device.

DESIGN CONCEPT FOR SNAP-ACTING TWO-WAY SHAPE MEMORY DEVICES

Snap-acting two way shape memory device can be obtained by using the design proposed by authors.Some essential parameters which characterize the properties of device have been pro- posed also in this paper.And the principle and method according to which a practical snap-acting device can be designed have been described.

Development of a Measurement Software for the Characterization of WORM Devices for Novel Memory Storage Applications

We hereby propose a software solution to perform high quality electrical measurements for the characterization of WORM (write-once read many), a new generation memory device which is being intensively studied for non-volatile data storage. The as-proposed software is completely based on .NET framework and sample C# code. The paper performed a relevant measurement based on this software. Working WORM devices, based on a polymeric matrix embedded with gold and copper sulfide nanoparticles, have been used for test measurements. The aim of this paper is to show the main steps to develop a fully working measurement software without using any expensive dedicated software.

Current Controlled Relaxation Oscillations in Ge_2Sb_2Te_5-Based Phase Change Memory Devices

The relaxation oscillation of the phase change memory （PCM） devices based on the Ge2Sb2Te5 material is investigated by applying square current pulses. The current pulses with different amplitudes could be accurately given by the independently designed current testing system. The relaxation oscillation across the PCM device could be measured using an oscilloscope. The oscillation duration decreases with time, showing an inner link with the shrinking threshold voltage Vth. However, the relaxation oscillation would not terminate until the remaining voltage Von reaches the holding voltage Vh. This demonstrates that the relaxation oscillation might be controlled by Von. The increasing current amplitudes could only quicken the oscillation velocity but not be able to eliminate it, which indicates that the relaxation oscillation might be an inherent behavior for the PCM cell.

New Superionic Memory Devices Can Provide Clues to the Human Memory Structure and to Consciousness

Since the work of Penrose and Hameroff the possibility is discussed that the location of human memory and consciousness could be connected with tubulin microtubules. If one would use superionic nano-materials rolled up to microtubules with an electrolyte inside the formed channels mediating fast ionic exchange of protons respectively lithium ions, it seems to be possible to write into such materials whole image arrays (pictures) under the action of the complex electromagnetic spectrum that composes these images. The same material and architecture may be recommended for super-computers. Especially microtubules with a protofilament number of 13 are the most important to note. We connected such microtubules before with Fibonacci nets composed of 13 sub-cells that were helically rolled up to deliver suitable channels. Our recent Fibonacci analysis of Wadsley-Roth shear phases such as niobium tungsten oxide , exhibiting channels for ultra-fast lithium-ion diffusion, suggests to use these materials, besides super-battery main application, in form of nanorods or microtubules as effectively working superionic memory devices for computers that work ultra-fast with the complex effectiveness of human brains. Finally, we pose the question, whether dark matter, ever connected with ultrafast movement of ordinary matter, may be responsible for synchronization between interactions of human brains and consciousness.

Design of an Electrically Written and Optically Read Non-volatile Memory Device Employing BiFeO3/Au Heterostructures with Strong Absorption Resonance

Exploiting new concepts for dense, fast, and nonvolatile random access memory with reduced energy consump- tion is a significant issue for information technology. Here we design an ＇electrically written and optically read＇ information storage device employing BiFeO3/A u heterostruetures with strong absorption resonance. The electro- optic effect is the basis for the device design, which arises from the strong absorption resonance in BiFeO3/Au heterostructures and the electrically tunable significant birefringence of the BiFeO3 film. We first construct a sim- ulation calculation of the BiFeO3/Au structure spectrum and identify absorption resonance and electro-optical modulation characteristics. Following a micro scale partition, the surface reflected light intensity of different polarization units is calculated. The results depend on electric polarization states of the BiFeO3 film, thus BiFeO3/Au heterostructures can essentially be designed as a type of electrically written and optically read infor- mation storage device by utilizing the scanning near-field optical microscopy technology based on the conductive silicon cantilever tip with nanofabricated aperture. This work will shed light on information storage technology.

Effect of Pulse and dc Formation on the Performance of One-Transistor and One-Resistor Resistance Random Access Memory Devices

We investigate the effect of the formation process under pulse and dc modes on the performance of one transistor and one resistor （1 T1R） resistance random access memory （RRAM） device. All the devices are operated under the same test conditions, except for the initial formation process with different modes. Based on the statistical results, the high resistance state （FIRS） under the dc forming mode shows a lower value with better distribution compared with that under the pulse mode. One of the possible reasons for such a phenomenon originates from different properties of conductive filament （CF） formed in the resistive switching layer under two different modes. For the dc forming mode, the formed filament is thought to be continuous, which is hard to be ruptured, resulting in a lower HRS. However, in the case of pulse forming, the filament is discontinuous where the transport mechanism is governed by hopping. The low resistance state （LRS） can be easily changed by removing a few trapping states from the conducting path. Hence, a higher FIRS is thus observed. However, the HRS resistance is highly dependent on the length of the gap opened. A slight variation of the gap length will cause wide dispersion of resistance.

The Development of Memory Alloy Satellite-Rocket Separation Device for Commercial Small Satellites

Non-pyrotechnic separation devices have been fully recognized for their high performance and high reliability.The focus of this paper is mainly around the development of memory alloy satellite and rocket separation devices.Due to the increasing demand for small-sized rockets and satellites,some suggestions and experiments for developing this new type of non-pyrotechnic device are proposed and conducted.

Dynamic resistive switching in a three-terminal device based on phase separated manganites

A three-terminal device based on electronic phase separated manganites is suggested to produce high performance resistive switching. Our Monte Carlo simulations reveal that the conductive filaments can be formed/annihilated by reshaping the ferromagnetic metal phase domains with two cross-oriented switching voltages. Besides, by controlling the high resistance state（HRS） to a stable state that just after the filament is ruptured, the resistive switching remains stable and reversible, while the switching voltage and the switching time can be greatly reduced.

Effect of Switching on Metal-Organic Interface Adhesion Relevant to Organic Electronic Devices

Considerable efforts are currently being devoted to investigation of metal-organic, organic-organic and organic-inorganic interfaces relevant to organic electronic devices such as organic light emitting diode (OLEDs), organic photovoltaic solar cells, organic field effect transistors (OFETs), organic spintronic devices and organic-based Write Once Read Many times (WORM) memory devices on both rigid and flexible substrates in laboratories around the world. The multilayer structure of these devices makes interfaces between dissimilar materials in contact and plays a prominent role in charge transport and injection efficiency which inevitably affect device performance. This paper presents results of an initial study on how switching between voltage thresholds and chemical surface treatment affects adhesion properties of a metal-organic (Au-PEDOT:PSS) contact interface in a WORM device. Contact and Tapping-mode Atomic Force Microscopy (AFM) gave surface topography, phase imaging and interface adhesion properties in addition to SEM/EDX imaging which showed that surface treatment, switching and surface roughness all appeared to be key factors in increasing interface adhesion with implications for increased device performance.

Status and Trends in Advanced SOI Devices and Materials

A review of recently explored effects in advanced SOI devices and materials is given.The effects of key device parameters on the electrical and thermal floating body effects are shown for various device architectures.Recent advances in the understanding of the sensitivity of electron and hole transport to the tensile or compressive uniaxial and biaxial strains in thin film SOI are presented.The performance and physical mechanisms are also addressed in multi-gate Si,SiGe and Ge MOSFETs.New hot carrier phenomena are discussed.The effects of gate misalignment or underlap,as well as the use of the back gate for charge storage in double-gate nanodevices and of capacitorless DRAM are also outlined.

A novel one-time-programmable memory unit based on Schottky-type p-GaN diode

In this work,a novel one-time-programmable memory unit based on a Schottky-type p-GaN diode is proposed.During the programming process,the junction switches from a high-resistance state to a low-resistance state through Schottky junction breakdown,and the state is permanently preserved.The memory unit features a current ratio of more than 10^(3),a read voltage window of 6 V,a programming time of less than 10^(−4)s,a stability of more than 108 read cycles,and a lifetime of far more than 10 years.Besides,the fabrication of the device is fully compatible with commercial Si-based GaN process platforms,which is of great significance for the realization of low-cost read-only memory in all-GaN integration.

In-memory computing to break the memory wall

Facing the computing demands of Internet of things(IoT)and artificial intelligence(AI),the cost induced by moving the data between the central processing unit(CPU)and memory is the key problem and a chip featured with flexible structural unit,ultra-low power consumption,and huge parallelism will be needed.In-memory computing,a non-von Neumann architecture fusing memory units and computing units,can eliminate the data transfer time and energy consumption while performing massive parallel computations.Prototype in-memory computing schemes modified from different memory technologies have shown orders of magnitude improvement in computing efficiency,making it be regarded as the ultimate computing paradigm.Here we review the state-of-the-art memory device technologies potential for in-memory computing,summarize their versatile applications in neural network,stochastic generation,and hybrid precision digital computing,with promising solutions for unprecedented computing tasks,and also discuss the challenges of stability and integration for general in-memory computing.

Performance improvement of charge trap flash memory by using a composition-modulated high-k trapping layer

A composition-modulated （HfO2）x（Al2O3）1-x charge trapping layer is proposed for charge trap flash memory by controlling the A1 atom content to form a peak and valley shaped band gap. It is found that the memory device using the composition-modulated （HfO2）x（Al2O3）l-x as the charge trapping layer exhibits a larger memory window of 11.5 V, improves data retention even at high temperature, and enhances the program/erase speed. Improvements of the memory characteristics are attributed to the special band-gap structure resulting from the composition-modulated trapping layer. Therefore, the composition-modulated charge trapping layer may be useful in future nonvolatile flash memory device application.

Numerical simulation study of organic nonvolatile memory with polysilicon floating gate

A polysilicon-based organic nonvolatile floating-gate memory device with a bottom-gate top-contact configuration is investigated,in which polysilicon is sandwiched between oxide layers as a floating gate.Simulations for the electrical characteristics of the polysilicon floating gate-based memory device are performed.The shifted transfer characteristics and corresponding charge trapping mechanisms during programing and erasing（P/E） operations at various P/E voltages are discussed.The simulated results show that present memory exhibits a large memory window of 57.5 V,and a high read current on/off ratio of ≈ 10~3.Compared with the reported experimental results,these simulated results indicate that the polysilicon floating gate based memory device demonstrates remarkable memory effects,which shows great promise in device designing and practical application.

TRANSFORMATION CHARACTERISTIC OF TWO WAY SHAPE MEMORY MATERIAL CONSTRAINED BY STRESS

The snap-acting transition and two way shape memory (TWSM) effect have been obtained in a TWSM spring made of Ni51Ti49 alloy using the constrained effect of stress on driving force of TWSM material.When the snap-acting transition has been realized:M_s= M_f and A_s=A_f;hysteresis is rectangular,the height (TWSM effect) and width (hysteresis) of the rectangle can be readjusted by means of constrained stress.The results of resistance measurments show that,the snap-acting TWSM effect mentioned above was supplied mainly from the transformation of P←→R.The thermodynamic model has also been proposed to ac- count for the snap-acting transformation.

末梢血采集部位轮换记忆器在快速血糖监测中的应用

目的:探讨末梢采血部位轮换记忆器在快速血糖监测中的应用效果。方法:选取2022年6月—10月在我科住院的合并糖尿病需要监测血糖的136例病人作为研究对象,按随机数字表法分为观察组与对照组,比较两组的疼痛视觉模拟评分(VAS)、病人监测血糖的依从性、病人对监测血糖的满意度、护士对使用末梢血采集部位轮换记忆器的满意度。结果:观察组VAS评分低于对照组,病人监测血糖的依从性、病人对监测血糖的满意度明显高于对照组,差异均有统计学意义(P<0.05)。结论:使用该记忆器能明显减轻病人的疼痛,提高病人血糖监测的依从性,且病人及护士对末梢血采集部位轮换记忆器的使用效果满意。