A fully integrated surface micromachined magnetic microactuatorwith a multilevel meander magnetic core

A fully integrated magnetic microactuator using surface micromachining techniques is presented. To achieve this device, low-resistance meander conductors located in a single plane were interwoven with multilevel meander magnetic cores. This `wrapped' solenoid (with the core wrapped around the conductor) was fabricated in a fully integrated fashion. A magnetic microactuator was realized by incorporating a surface micromachined nickel-iron cantilever beam as part of the magnetic circuit of the core. The nickel-iron cantilever beam was 2.5 μm thick, 25 μm wide, and 780 μm long, and the magnetic circuit contained seventeen turns of meander-type solenoid coils. Cantilever beam tip deflection of 6 μm in the vertical direction was achieved when a DC voltage less than 1 V (and resulting drive current of 800 mA) was applied to the coils. This fully integrated multilevel topology offers advantages in a variety of micromagnetic applications, where actuators can be fabricated on the same substrate with an integrated circuit and actuated with low voltages     

Fully integrated magnetically actuated micromachined relays

A fully integrated magnetically actuated micromachined relay has been successfully fabricated and tested. This particular device uses a single-layer coil to actuate a movable upper magnetically responsive platform. The minimum current for actuation was 180 mA, resulting in an actuation power of 33 mW. Devices have been tested which can make and break 1.2 A of current through the relay contacts when the relay is electromagnetically switched. Operational lifetimes in excess of 850000 operations have been observed. Contact resistances as low as 22.4 mΩ have been observed under electromagnetic actuation. Magnetic and structural finite-element (FE) simulations have been performed using ANSYS to calculate both the actuation and contact forces     

A monolithically integrated surface micromachined touch mode capacitive pressure sensor

A monolithically integrated surface micromachined touch mode capacitive pressure sensor and its interface circuits are presented. The device includes the capacitance to voltage, and capacitance to frequency converters on the same chip. The sensor is fabricated using a surface micromachining technology, which is processed simultaneously with a conventional 2.0-μm double-poly, double-metal n-well CMOS process. The performance of the integrated sensor meets the design specifications of good linearity and good stability. Evaluation results on the completed ‘sensor and circuit' chip are presented.     

一种应用于无线传感器网络的全集成接收信号强度指示器

设计了一种应用于无线传感器网络(WSNs),可以在1.2V电压工作的,全集成接收信号强度指示器(RSSI).介绍了对数放大器的基本原理,改进了直流偏移消除电路结构,利用隔级反馈使限幅放大器部分更加易于全集成.改进了全波整流电路,使其能工作在低电压,功耗更低,同时大大提高了工艺稳定性和温度稳定性.采用0.18 μm CMOS工艺,仿真结果显示:在1.2V电源电压时,RSSI的直流电流小于0.6mA,2 MHz输入信号频率,输入动态范围为-85 ～-10 dBm时,RSSI的线性误差小于±0.5 dB.     

Bulk micromachined tunneling tips integrated with positioning actuators

We have successfully developed an integrated micromechanical system for controlling tunneling current. A pair of nanoscale tunneling tips have been integrated with a silicon micromachined electrostatic actuator of high-aspect ratio. The tip sharpness has been observed to be as sharp as commercial tips by scanning over surface of carbon graphite as an atom scale. We have also succeeded to observe the tunneling current in the air and in the vacuum condition (in TEM).     

A two-dimensional optical cross-connect with integrated waveguides and surface micromachined crossbar switches

The design, fabrication and test results of an all-optical cross-connect, which uses electrostatically actuated micromechanical digital mirrors to steer optical signals in a network of planar waveguides, are presented. The substrate consists of a network of spliced planar waveguides on silica substrates. The switches, located at the waveguide intersections, are formed with an electroplated T-structure consisting of a horizontal perforated square plate suspended by four elastic beams. When operated, the horizontal plate is pulled up making the mirror move out of the optical path thus steering the beam. An 8×8 switch array has been fabricated and tested. Actuation and relaxation switching times near 3 ms have been demonstrated with an actuation voltage of 120 V. The optical insertion loss for the array typically varied from 2.3 dB for a single trench in the optical path (shortest optical path) to 8 dB for 15 trenches in the optical path (longest optical path).     

A rapid magnetic particle driven micromixer

Performances of a magnetic particle driven micromixer are predicted numerically. This micromixer takes advantages of mixing enhancements induced by alternating actuation of magnetic particles suspended in the fluid. Effects of magnetic actuation force, switching frequency and channel’s lateral dimension have been investigated. Numerical results show that the magnetic particle actuation at an appropriate frequency causes effective mixing and the optimum switching frequency depends on the channel’s lateral dimension and the applied magnetic force. The maximum efficiency is obtained at a relatively high operating frequency for large magnetic actuation forces and narrow microchannels. If the magnetic particles are actuated with a much higher or lower frequency than the optimum switching frequency, they tend to add limited agitation to the fluid flow and do not enhance the mixing significantly. The optimum switching frequency obtained from the present numerical prediction is in good agreement with the theoretical analysis. The proposed mixing scheme not only provides an excellent mixing, even in simple microchannel, but also can be easily applied to lab-on-a-chip applications with a pair of external electromagnets.     

Framework of fully integrated hybrid systems

A framework of fully integrated hybrid systems (HSs) is proposed for the development and management of HS which involve databases, advanced user interfaces, symbolic systems, and artificial neural networks. This framework provides a common input–output interface among those HS modules developed on the framework, with a completely two-directional flow control and a highly parallel processing. This integration framework facilitates the incorporation of heterogeneous modules, together with their subsequent management and updating.     

CMOS fully digital integrated pressure sensors

Most commercially available silicon pressure transducers are based on a Wheatstone bridge configuration and given an analogue output signal. These devices are generally very sensitive to noise and require complicated circuits (by using passive components) for temperature and non-linearity compensation. This limits the transducer accuracy and increases the calibration cost. To overcome these problems, a new generation of pressure transducers with digital output, based on MOSFET ring oscillators, has been developed. A fully digital integrated pressure sensor and data-acquisition procedures will be presented.     

A design methodology for fully integrated MEMS and NEMS Pierce oscillators

This work proposes a generic methodology to evaluate the feasibility of designing a Pierce oscillator based on a micro or nanoresonator fabricated with any given CMOS technology and with the constraint of using only one single active transistor. Both the design and the transimpedance gain of the electronics are analytically determined for resonators with capacitive or resistive detection. This approach is applied and validated in the case of (a) an electrostatically actuated clamped-clamped beam resonator using a capacitive transduction, and (b) a piezoresistive crossbeam, both based on a standard 0.13 μm CMOS technology.     

A wireless powered fully integrated SU-8-based implantable LC transponder

In this work, we report a SU-8-based fully integrated miniaturized inductively powered LC transponder for generic implantable wireless sensor applications. It consists of a 1 mm diameter octagonal spiral inductor and a micro fabricated MIM (metal insulator metal) capacitor. Polyvinylidene Fluoride–Trifluoroethylene (PVDF–TrFE) copolymer is applied as a dielectric material for the capacitor fabrication due to its high dielectric constant. The 1 mm diameter, 154 nH spiral inductor is built on top of the capacitor. The capacitor and the inductor are in parallel connection through SU-8 via holes. SU-8 is used as a packaging material due to its biocompatibility, and also it serves as an insulator between the capacitor and the spiral inductor. The operating frequencies of the LC tanks are decided by the sizes of the capacitors (45 × 45, 55 × 55, 95 × 95 and 100 × 100 μm), and measured operating frequency range is from 385 to 485 MHz. The fabricated LC tanks are held to the power transmitting coil coaxially at distances of 2, 5, 7 and 10 mm, and rectified induced voltage at the LC tank is 8.5 V with 29 dBm input power at a 5 mm distance.     

Scale-free fully informed particle swarm optimization algorithm

This paper proposes a novel PSO algorithm, referred to as SFIPSO (Scale-free fully informed particle swarm optimization). In the proposed algorithm a modified Barabási-Albert (BA) model [4] is used as a self-organizing construction mechanism, in order to adaptively generate the population topology exhibiting scale-free property. The swarm population is divided into two subpopulations: the active particles and the inactive particles. The former fly around the solution space to find the global optima; whereas the latter are iteratively activated by the active particles via attaching to them, according to their own degrees, fitness values, and spatial positions. Therefore, the topology will be gradually generated as the construction process and the optimization process progress synchronously. Moreover, the cognitive effect and the social effect on the variance of a particle’s velocity vector are distributed by its “contextual fitness” value, and the social effect is further distributed via a time-varying weighted fully informed mechanism that originated from [27]. It is proved by the results of comparative experiments carried out on eight benchmark test functions that the scale-free population topology construction mechanism and the weighted fully informed learning strategy can provide the swarm population with stronger diversity during the convergent process. As a result, SFIPSO obtained success rate of 100% on all of the eight test functions. Furthermore, SFIPSO also yielded good-quality solutions, especially on multimodal test functions. We further test the network properties of the generated population topology. The results prove that (1) the degree distribution of the topology follows power-law, therefore exhibits scale-free property, and (2) the topology exhibits “disassortative mixing” property, which can be interpreted as an important condition for the reinforcement of population diversity.     

Single core fully integrated CMOS micro-fluxgate magnetometer

A new fully integrated 2D micro-fluxgate magnetometer is presented. This magnetometer is integrated in a standard CMOS process and uses a ferromagnetic core integrated on the chip by a photolithographic post-process compatible with the integrated circuit technology. The cross-shaped ferromagnetic core is placed diagonally above four excitation coils, two for each measurement axis. A novel electronic signal extraction technique is presented. The integrated 2D magnetometer exhibits a sensitivity of 160 V/T and a linear range of ±50 μT. The magnetic equivalent noise spectral density is 70 nT/√Hz at 1 Hz, and the total power consumption is as low as 17 mW for the 5 V power supply.     

一种扭摆式硅微机械加速度传感器

介绍了一种基于体硅微机电系统(MEMS)工艺制作的扭摆式硅微机械加速度传感器,对制作过程的一些工艺问题进行探讨,并提出相应的解决办法,主要涉及到硅-玻璃阳极键合、结构释放等关键工艺。对测试结果进行了初步分析,分辨力可以达到1mgn,测试±1gn范围内线性度可以达到99.99%。     

A post-CMOS micromachined lateral accelerometer

In a post-complementary metal-oxide-semiconductor (CMOS) micromachining technology, the process flow enables the integration of micromechanical structures with conventional CMOS circuits which are low-cost and readily available. This paper presents a lateral capacitive sensing accelerometer fabricated in the post-CMOS process. Design advantages include electrically isolated multimetal routing on microstructures to create full-bridge capacitive sensors, and integration to increase transducer sensitivity by minimizing parasitic capacitance. In a size of 350 μm by 500 μm, this accelerometer has a 1 mG/√(Hz) resolution and a linear range of at least ±13 G. The fundamental limitations of mechanical and electronic noise for acceleration sensing are addressed     

A 65 mW fully integrated UHF-band CMMB tuner in 65 nm CMOS process

A low power fully integrated digital TV tuner chip for China Mobile Multimedia Broadcasting(CMMB) application is presented.Based on direction conversion architecture,analog 8th-order filter/gain stages utilizing high power efficient operation-amplifiers and a ΣΔ fractional-N phase locked loop(PLL) with one voltage controlled oscillator(VCO) covering 4.8—7.2 GHz is proposed for low power and small chip area.The tuner is implemented in 65 nm CMOS process with low noise amplifier(LNA) matching network and phase locked loop(PLL) filter integrated on chip,occupying a chip area of 4.83 mm2.The measured noise figure(NF) is less than 3.2 dB over CMMB UHF band(470—798 MHz).A total power consumption of 65 mW(54 mA from 1.2 V supply) is achieved.     

A high efficiency inductor‐less broadband fully integrated CMOS power amplifier

This work presents the design and implementation of a novel broadband completely inductor‐less 300 MHz–2.4 GHz power amplifier (PA) in 180 nm CMOS, primarily for applications in the ultrahigh frequency (UHF) industrial scientific and medical band. This is capable of delivering up to 15.6 dBm saturated output power with an associated peak power added efficiency of 31% in measurement. Although amplifiers with higher output power have been reported, this amplifier occupies only 0.086 mm² and does not require any off chip component for its operation, even at the UHF band. It also achieves the highest power density among a similar class of PA's below 10 GHz. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:311–320, 2015.     

A liquid-filled buoyancy-driven convective micromachined accelerometer

A novel class of accelerometer, based on the buoyancy of a heated fluid within a micromachined cavity, has previously been developed and reported. Based on dimensional analysis and computational modeling, it is predicted that the sensitivity of the accelerometer can be increased by several orders of magnitude over previously reported results by choosing a suitable liquid as the working fluid, though this increased sensitivity comes at the cost of an increased response time. A liquid-filled accelerometer is constructed; its sensitivity and response time are measured, and shown to be consistent with theoretical predictions and with the results of finite-element analysis. It is noted that the existing literature provides no basis for predicting the effect of Prandtl number on the sensitivity and response time of the accelerometer. The prediction of response time requires analysis of the transient response of the heated fluid to a sudden acceleration. This is a novel problem: previous studies of transient convection have focused on the effects of a newly imposed temperature differential in an existing gravity field, rather than a newly imposed acceleration on an existing thermal field. An approximate expression for response time as a function of radius ratio and Prandtl number is developed by curve-fitting to the results of FLOTRAN simulation.