Simple Power Consumption Research Articles

Laser beam steering of 532 nm using a power-efficient focal plane array

Laser beam steering is important for classical and quantum information processing. On-chip beam steering is a major motivation for developing large-scale photonic integrated circuits such as optical phased arrays. A major challenge for such arrays is to simultaneously control a large number of on-chip phase shifters, which requires a complicated analog control algorithm and rapidly increasing power consumption. We report a green light (532 nm) 1 × 16 focal plane array photonic integrated circuit with simple control and low power consumption. Fabricated on a silicon nitride platform, the focal plane array achieves angular beam steering over a 10° field of view, with ultra-low electrical power consumption (4 × 3.1 mW).

A high precision and low power consumption switching capacitor readout circuit

In this paper, a high precision and low power switching capacitor readout circuit for MEMS sensors is proposed. The capacitance readout circuit is realized by using the total difference separation loop structure composed of a switching capacitor charge amplifier. In order to reduce the aggravation of common-mode parasitic capacitance to the input offset error and amplifier gain error in the readout circuit, the input common-mode feedback compensation structure and oversampled successive approximation (OSA) readout technology are introduced. In addition, the circuit adopts a non-overlapping nested clock to reduce charge injection and improve output accuracy. Based on SMIC 0.18 μm CMOS technology, the circuit can recognize 0-0.2 pF capacitance signals and convert them into voltage signals, achieving good linear fitting. When the common-mode parasitic capacitance is 1-16 p, it has good resistance to common-mode parasitic capacitance, and the precision of the capacitor readout circuit is increased by 3.9%. Compared with traditional readout circuits, it has a simple structure and low power consumption.

An Account of Natural Material-Based Nonvolatile Memory Device

The development in electronic sector has brought a remarkable change in the lifestyle of mankind. At the same time, this technological advancement results in adverse effect on environment due to the use of toxic and non-degradable materials in various electronic devices. With the emergence of environmental problems, the green, reprogrammable, biodegradable, sustainable and environmental-friendly electronic devices have become one of the best solutions for protecting our environment from hazardous materials without compromising the growth of the electronic industry. Natural material has emerged as the promising candidate for the next generation of electronic devices due to its easy processing, transparency, flexibility, abundant resources, sustainability, recyclability, and simple extraction. This review targets the characteristics, advancements, role, limitations, and prospects of using natural materials as the functional layer of a resistive switching memory device with a primary focus on the switching/memory properties. Among the available memory devices, resistive random access memory, write once read many unipolar memory, etc., devices have a huge potential to become the nonvolatile memory of the next generation owing to their simple structure, high scalability, and low power consumption. The motivation behind this work is to promote the use of natural materials in electronic devices and attract researchers toward a green solution of hazardous problems associated with the electronic devices.

An Intelligent Glove of Synergistically Enhanced ZnO/PAN-Based Piezoelectric Sensors for Diversified Human–Machine Interaction Applications

Human–machine interaction is now deeply integrated into our daily lives. However, the rigidity and high-power supply of traditional devices limit their further development. Herein, a high-performance flexible piezoelectric sensor (HFPS) based on a novel zinc oxide/polyacrylonitrile/Ecoflex (ZnO/PAN/Ecoflex) composite membrane is proposed. Due to the synergistic piezoelectricity of ZnO and PAN, the output voltage/current of the HFPS is increased by 140%/100% compared to the pure Zno/Ecoflex composite membrane. Furthermore, the fabricated HFPSs also have excellent sensitivity, linearity, stability and flexibility under periodic pressure. On this basis, due to its flexibility, stretchability and battery-free characteristics, a self-powered HFPS-based intelligent glove is proposed to wirelessly control diverse electronic systems through human hand gestures. In the meanwhile, the intelligent glove has been successfully applied to car two-dimensional motion, light bulb control and fan control. With the advantages of simple operation, portability and low power consumption, the glove is expected to provide new application prospects for human–machine interaction systems.

Superior resistive switching performance in SnO2 nanoparticles embedded TiO2 nanorods-based thin films

Resistive random-access memories are ideal candidates for next-generation non-volatile memories due to their simple structure, fast response, and low power consumption. One-dimensional nanostructured memories are of particular importance owing to their electron transport confinement in individual components (such as nanorods/nanowires) that can provide extra control to finely tune the electrical performance for stable and reliable memory operations. In this work, vertically oriented one-dimensional TiO2 nanorods were fabricated via a simple and facile solvothermal technique. Besides, SnO2 nanoparticles were embedded on TiO2 nanorods matrix (to form a nanocomposite) and their resistive switching characteristics were evaluated and compared. Although, both devices expressed good resistive switching behavior. However, the nanocomposite device showed superior switching performance than the control (TiO2 nanorods) one. Moreover, the nanocomposite device demonstrated additional features of multilevel data storage and the prediction of switching probabilities at lower potentials to be applied in neuromorphic computing. The governing resistive switching mechanism was explored, and the role of oxygen vacancies was identified as critical for the switching and charge transport mechanism in the investigated devices.

Stretchable Iontronic Pressure Sensor Array With Low Crosstalk and High Sensitivity for Epidermal Monitoring

Soft piezocapacitive sensor, owing to its simple assembly and low power consumption, draws intensive interests for physiological monitoring. However, crosstalk between proximity sensing units and limited mechanically stretching suppressed its practical application for conventional capacitive sensor array. Here we report a stretchable iontronic pressure sensor (SIPS) array with low proximate crosstalk for epidermal monitoring. Benefiting from electric double layer (EDL) capacitance effect between robust aramid nanofiber (ANF) /MXene (Ti3C2Tx) composite electrode and ionic film, the SIPS exhibits a high sensitivity up to 521.69 kPa−1, low limit of detection (0.22 Pa), broad linear sensing range (200 kPa) and rapid response time (17 ms) as well as long-term stable working durability for 10,000 cycles. The serpentine island bridge structure enables the SIPS array to stretch up to 40%, allowing pulse and grip monitoring of a bent wrist and finger, respectively, through processing circuits. This demonstrates the promising application prospects in vital physiological monitoring.

Numerical Solving of Radiation Geometrical Inverse Problem

Compared to large satellites, on-board electronics of microsatellites, such as microprocessors, are more exposed to radiation and high-energy particles. This problem can lead to single-event upsets, which might generate false commands such as thruster firing or switching heaters on or off. In some cases, these upsets cause the loss of a spacecraft orientation and endanger the whole mission. This makes important to elaborate a reliable and robust attitude determination system which will enable us to correct and recover the spacecraft’s attitude after a failure. It must have a simple design, low mass, and power consumption. In this paper we suggest a new method of determination of spacecraft’s attitude based on heat fluxes analysis that could form the basis of such a system. In order to develop it we have to solve two inverse problems sequentially. The first inverse problem is the estimating of heat fluxes absorbed by the spacecraft surface. The second one is to determine the spacecraft’s attitude based on the estimated values of radiative heat fluxes. This paper is dedicated to the solution of the second inverse problem.

Linear flexible capacitive sensor with double helix structure based on multi-needle water-bath electrospinning technology

Capacitive flexible sensors stand out due to their advantages of simple structure, strong adaptability and low power consumption, and become the mainstream technology for the preparation of wearable flexible devices. In this study, polyamide 6 (PA6) nanofibers were coated on the surface of a silver-coated nylon (SCN) core yarn using a novel multi-needle water-bath electrospinning method. The SCN/PA6 nanofiber core-spun yarns were prepared, and linear flexible capacitive sensors with a double helix structure (double helix structure capacitive sensors, DHSCSs) were produced by winding two nanofiber core-spun yarns in parallel, with different winding densities, on elastic rubber strings. We then characterized the nanofiber core-spun yarn, analyzed its sensing performance, and explored an application in human motion monitoring. Our results confirm that a nanofiber coating with a complete structure can be formed on the surface of the SCN core yarn by multi-needle water-bath electrospinning. The nanofiber diameter was in the 80–100 nm range, which provides a soft and deformable dielectric layer for the sensor. The capacitance of the DHSCSs gradually decreased with an increase in strain. When the strain was small, it exhibited good linearity (R 2 > 0.99) and sensitivity (gauge factor of ∼4). With an increase in strain, the linearity and sensitivity of the DHSCSs gradually decreased. The capacitances of the DHSCSs were stable under extended duration cyclic stretching, and their repeatability and stability were good. At different tensile speeds, the sensing performance of the DHSCSs did not change, and the capacitance change was not affected by the tensile speed. The higher winding density of the sensor made it more sensitive. The DHSCS could monitor intermittent and continuous knee bending and walking, effectively monitoring human motion in real time. This sensor has the potential for application in flexible wearable human motion, health monitoring, and other fields.

Performance Analysis of Vilnius Chaos Oscillator-Based Digital Data Transmission Systems for IoT

The current work is devoted to chaos oscillator employment in digital communication systems for IoT applications. The paper presents a comparative performance analysis of two different chaos data transmission systems: frequency-modulated chaos shift keying (FM-CSK) and quadrature chaos phase-shift keying (QCPSK), and a comparison to their non-chaotic counterparts: frequency-shift keying (FSK) and quadrature amplitude modulation (QAM). For both chaotic communication systems, the Vilnius oscillator and substitution method of chaotic synchronization are chosen due to simple circuitry implementation and low power consumption properties. The performance of the systems in the fading channel with additive white Gaussian noise (AWGN) is evaluated. Also, the systems’ performance in the case phase noise is investigated, and the benefits of chaotic waveforms employment for data transmission are demonstrated.

Noncontact Sleeping Heartrate Monitoring Method Using Continuous-Wave Doppler Radar Based on the Difference Quadratic Sum Demodulation and Search Algorithm.

Continuous-wave doppler radar, which has the advantages of simple structure, low cost, and low power consumption, has attracted extensive attention in the detection of human vital signs. However, while respiration and heartbeat signals are mixed in the echo phase, the amplitude difference between the two signals is so large that it becomes difficult to measure the heartrate (HR) from the interference of respiration stably and accurately. In this paper, the difference quadratic sum demodulation method is proposed. According to the mixed characteristics of respiration and heartbeat after demodulation, the heartbeat features can be extracted with the help of the easy-to-detect breathing signal; combined with the constrained nearest neighbor search algorithm, it can realize sleeping HR monitoring overnight without body movements restraint. Considering the differences in vital-sign characteristics of different individuals and the irregularity of sleep movements, 54 h of sleep data for nine nights were collected from three subjects, and then compared with ECG-based HR reference equipment. After excluding the periods of body turning over, the HR error was within 10% for more than 70% of the time. Experiments confirmed that this method, as a tool for long-term HR monitoring, can play an important role in sleeping monitoring, smart elderly care, and smart homes.

Frequency-specific highly sensitive acoustic sensor using a piezoresistive cantilever element and parallel Helmholtz resonators

Acoustic sensors for specific-frequency detection are used in various applications, and their sensitivity improvement has been attracting significant attention. Mechanical acoustic resonator technology is an effective method because of its simple structure and low power consumption. A Helmholtz resonator (HR) is a typical mechanical resonator; however, previous HRs for an acoustic sensor were attached to the rear of the sensing element, which was unsuitable for a differential pressure (DP) sensor that blocks the pressure wave propagating through the sensor chip. This paper proposes a micro-electro-mechanical system (MEMS)-based acoustic sensor, enhanced by a front-mounted parallel HR array, which is suitable for a DP sensor-type element. A piezoresistive cantilever-type DP sensor was used as the sensing element because of its high sensitivity to acoustic waves in its mechanical resonant frequency (RF) range. Its sensitivity was enhanced by attaching an HR array to the DP sensor, like a cap. We designed and fabricated a piezoresistive cantilever with dimensions 80 × 80 × 0.2 µm and an RF of 4.5 kHz, and four HR arrays with an RF close to that of the cantilever. The sensor responses to acoustic waves with and without the HRs were evaluated. The developed sensor with the HR realized three times higher sensitivity than those without the HR at the RF. The obtained acoustic pressure resolution was approximately 4 mPa. • A MEMS piezoresistive cantilever element and parallel Helmholtz resonator are combined for a frequency-specific highly sensitive acoustic sensor. • Resonant frequencies of the cantilever and Helmholtz resonator are matched to enhance the sensitivity. • A sensor realizes acoustic pressure resolution of approximately 4 mPa at the resonant frequency.

A Highly Sensitive and Flexible Capacitive Pressure Sensor Based on Alignment Airgap Dielectric.

Flexible capacitive pressure sensors with a simple structure and low power consumption are attracting attention, owing to their wide range of applications in wearable electronic devices. However, it is difficult to manufacture pressure sensors with high sensitivity, wide detection range, and low detection limits. We developed a highly sensitive and flexible capacitive pressure sensor based on the porous Ecoflex, which has an aligned airgap structure and can be manufactured by simply using a mold and a micro-needle. The existence of precisely aligned airgap structures significantly improved the sensor sensitivity compared to other dielectric structures without airgaps. The proposed capacitive pressure sensor with an alignment airgap structure supports a wide range of working pressures (20–100 kPa), quick response time (≈100 ms), high operational stability, and low-pressure detection limit (20 Pa). Moreover, we also studied the application of pulse wave monitoring in wearable sensors, exhibiting excellent performance in wearable devices that detect pulse waves before and after exercise. The proposed pressure sensor is applicable in electronic skin and wearable medical assistive devices owing to its excellent functional features.

Redesign of water-diesel emulsion fuel mixer

Emissions and fuel consumption are essential parameters to indicate the working of a combustion engine. This paper discusses the methods to achieve lower emissions and efficient fuel consumption. One of the methods is by making emulsion fuel. The emulsion-making methods are surfactant emulsion, micro-emulsion, ultrasonic emulsion, and real-time emulsion non-surfactant (RTES). In the research, the emulsion fuel is a mixture of B30 Biodiesel and water without surfactant that is supplied in real-time after being mixed in a mixer. The ratio is 85% biodiesel and 15% water. The RTES mixer in the old model has a big size, and high-power consumption of about 150-433,5 W. This research's purpose is to develop a simple design and low power consumption of the RTES Mixer. The new RTES mixer design only needs 150 W motor power. Its dimension is more superficial and produces tiny droplets with a main diameter range between 0.1 to 0.5 ?m, with good-mixed visually.

Linear Frequency Modulation of NbO2-Based Nanoscale Oscillator With Li-Based Electrochemical Random Access Memory for Compact Coupled Oscillatory Neural Network.

Oscillatory neural network (ONN)-based classification of clustered data relies on frequency synchronization to injected signals representing input data, showing a more efficient structure than a conventional deep neural network. A frequency tunable oscillator is a core component of the network, requiring energy-efficient, and area-scalable characteristics for large-scale hardware implementation. From a hardware viewpoint, insulator-metal transition (IMT) device-based oscillators are attractive owing to their simple structure and low power consumption. Furthermore, by introducing non-volatile analog memory, non-volatile frequency programmability can be obtained. However, the required device characteristics of the oscillator for high performance of coupled oscillator have not been identified. In this article, we investigated the effect of device parameters of IMT oscillator with non-volatile analog memory on coupled oscillators network for classification of clustered data. We confirmed that linear conductance response with identical pulses is crucial to accurate training. In addition, considering dispersed clustered inputs, a wide synchronization window achieved by controlling the hold voltage of the IMT shows resilient classification. As an oscillator that satisfies the requirements, we evaluated the NbO2-based IMT oscillator with non-volatile Li-based electrochemical random access memory (Li-ECRAM). Finally, we demonstrated a coupled oscillator network for classifying spoken vowels, achieving an accuracy of 85%, higher than that of a ring oscillator-based system. Our results show that an NbO2-based oscillator with Li-ECRAM has the potential for an area-scalable and energy-efficient network with high performance.

Investigation of a novel ring-cusp magnetically confined plasma bridge neutralizer.

The plasma bridge neutralizer (PBN) based on a tungsten filament is a promising technique of a thermionic DC electron source where a hot filament is immersed in an inert gas flow and electrons are "bridged" from a small orifice to the ion beam. PBNs have been widely used in space propulsion and industrial applications due to their relatively simple structure and low power consumption. However, they have well-known disadvantages, namely, low emission current density and short lifetime. In this article, we propose a novel ring-cusp magnetically confined PBN (RCM-PBN) to address these issues. In the RCM-PBN, electrons are confined by a ring-cusp magnetic field, which improves the ionization efficiency and reduces the discharge chamber wall losses. Electrical insulation of the orifice plate from the chamber wall prevents a large number of electrons from being collected by the orifice plate, which greatly improves the extracted electron current. The effects of different operating parameters on the extracted electron current were studied through experiments. It was found that the increase in the extracted electron current with the extraction voltage was related to the anode spot formation. Analysis of the gas utilization factor and electron extraction cost shows that the optimal operating condition was obtained at an argon mass flow rate of 1.2 SCCM and a heater power of 45W. At its optimum, a stable electron current of 1.1A was extracted from the RCM-PBN with a gas utilization factor of 12.8 and an electron extraction cost of 143 W/A.

Multi-wavelength 128 Gbit s−1 λ −1 PAM4 optical transmission enabled by a 100 GHz quantum dot mode-locked optical frequency comb

Semiconductor mode-locked lasers (MLLs) with extremely high repetition rates are promising optical frequency comb (OFC) sources for their usage as compact, high-efficiency, and low-cost light sources in high-speed dense wavelength-division multiplexing transmissions. The fully exploited conventional C- and L- bands require the research on O-band to fulfil the transmission capacity of the current photonic networks. In this work, we present a passive two-section InAs/InGaAs quantum-dot (QD) MLL-based OFC with a fundamental repetition rate of ∼100 GHz operating at O-band wavelength range. The specially designed device favours the generation of nearly Fourier-transform-limited pulses in the entire test range by only pumping the gain section while with the absorber unbiased. The typical integrated relative intensity noise of the whole spectrum and a single tone are −152 and −137 dB Hz−1 in the range of 100 MHz–10 GHz, respectively. Back-to-back data transmissions for seven selected tones have been realised by employing a 64 Gbaud four-level pulse amplitude modulation format. The demonstrated performance shows the feasibility of the InAs QD MLLs as a simple structure, easy operation, and low power consumption OFC sources for high-speed fibre-optic communications.

A high-resolution electric field sensor based on piezoelectric bimorph composite

The rapid development of the internet of things technology has led to great demand for intelligent electric field sensor (EFS). Several working principles have been proposed, however major challenges remain existed for the requirements of EFS with low-cost, large-range, and high-resolution. In this paper, an EFS based on piezoelectric (PE) bending effect using d 31 mode is developed, where a bending strain is induced on the sandwiched bimorph structure of PZT/PDMS/PZT under an applied electric field, and the capacitance value of the PDMS layer reveals detectable variation. We demonstrate an EFS operating at the stress-mediated coupling between PE ceramic and elastic dielectric polymer, which reveals advantages such as simple fabrication process, low-cost and low power consumption. Due to the sandwiched bimorph structure, the strain caused by the electric field can be effectively transferred to improve the resolution of the device. The constitutive equations for the sandwiched bimorph structure are built, and the working principle of the proposed EFS is demonstrated. The EFS exhibits high sensitivity under both AC and DC electric fields, with a resolution of 0.1 V cm−1 in the range of −3 to 3 kV cm−1. The proposed sensor provides an alternative solution for power equipment fault diagnosis, power frequency electric field detection, etc.

Hydrodynamic Bearing Structural Design of Blood Pump Based on Axial Passive Suspension Stability Analysis of Magnetic–Hydrodynamic Hybrid Suspension System

Rotor suspension stability is one of the important performance indexes of a blood pump and the basis of determining whether the blood pump can be used in a clinic. Compared with the traditional magnetic suspension system, a single-winding, bearingless motor has the advantages of a compact structure, simple control system and low power consumption. In this pursuit, the present study aimed to envisage and design the magnetic suspension system coupled with a single-winding bearingless motor and permanent magnet bearings, establish the theoretical models of axial force and electromagnetic torque, and calculate the stiffness of the magnetic suspension system at the equilibrium point. Addressing the problem of the negative axial stiffness of the magnetic suspension system being negative, which leads to the instability of the suspension rotor, the hydrodynamic bearing structure was proposed and designed, and the critical stiffness to realize the stable suspension of the rotor was obtained based on the stability criterion of the rotor dynamics model. The optimal structural parameters of the hydrodynamic bearing are selected by integrating various factors based on the solution of the Reynolds equation and a stiffness analysis. Furthermore, the vibration experiment results proved that the blood pump rotor exhibited a good suspension stability, and the maximum offset under the impact external fluid was no more than 2 μm.

Highly Sensitive Capacitive Pressure Sensor Based on a Micropyramid Array for Health and Motion Monitoring

AbstractFlexible capacitive pressure sensors with simple structure and low power consumption have attracted great interest because of their promising applications in wearable electronics. However, assembling a pressure sensor with high sensitivity, low detection limit, and wide dynamic range is still a big challenge. Here, a sandwich‐like, flexible capacitive pressure sensor is reported with micropyramid array electrode and porous dielectric layer. Under external stimulus pressure, the distance between two electrodes, and dielectric constant of dielectric layer will change simultaneously, resulting in high sensitivity (2.51 kPa−1) of the sensor. Due to the micropyramid array electrode, the sensor exhibits low detection limit (2.0 Pa), fast response speed (84 ms), wide working range (>10 kPa), and high stability (>5000 dynamic cycles). Finite‐element analysis also reveals that the larger duty ratio and altitude of micropyramid arrays lead to higher sensor sensitivity. By depicting the deformation of micropyramid during compression, the sensing mechanism of these sensors is discovered, providing a potential direction for developing sensitivity and linear range. Additionally, the sensor has been demonstrated to be efficient in monitoring human motion, such as muscle activation and rope skipping, showing high potential in the field of sport wearable equipment.

Auto‐monitoring System for Residual Current Circuit Breakers

Residual current circuit breakers (RCCBs) are used to provide electric shock protection, initial and periodical verification is necessary to check the effectiveness of RCCBs. This paper presents an auto‐monitoring system with simple application circuit and low power consumption, which can test the function of the current transformer, silicon controlled rectifier (SCR), tripping solenoid, controller and other components of the residual current circuit breaker (RCCB) periodically. This test can be completed without disrupting power to the load or compromising normal function of the RCCB, and power denial or visual alarm can be provide after a fault is detected. A simulated residual current is generated periodically, and the response of these components is monitored by the system for functional verification. In this system, the signal that triggers the SCR is limited near the end of the positive half cycle of the hot line under the test mode, in accordance with the tripping characteristic of the RCCB, the functional verification will not disrupt the power to the load. Under the work mode, the signal that triggers the SCR is consistent with the tripping signal of the RCCB controller, guaranteeing the normal function of the RCCB. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.