Presliding hysteresis damping of LuGre and Maxwell-slip friction models

In this paper, the damping properties of presliding hysteresis are explored for the LuGre and Maxwell-slip friction models. Taking out of consideration the classical linear viscous damping and Stribeck effect, the nonlinear damping of force–displacement hysteresis is analyzed, in Lyapunov sense, for the motion dynamics. Based thereupon the simple but straightforward criteria of model’s parametrization are derived for kinetic friction to be dissipative. Further we show a related experimental example of presliding hysteresis friction response in vicinity to zero velocity.     

Time Resolved Imaging: From logical states to events,a new and efficient pattern matching method for VLSI analysis

Time Resolved Imaging (TRI) allows real time imaging of transitions in CMOS gates even for very deep submicron technologies at low power supply voltage. Anyway, the measured timing information differs from waveform measurement where logical states are easily extracted. We first introduce logical event with a 1 value when we have transition from one logical state to its complement (0–1 or 1–0) or 0 value when there is no change between 2 vectors. Events can be extracted from TRI database and then used for a very accurate and efficient pattern matching method. In this paper, we demonstrate how we move from logical state to events and the extreme accuracy of pattern matching. Results are shown on 45 nm CMOS technology.     

Dye-doped submicron fiber waveguides composed of hole- and electron-transport materials

Dye-doped, submicron fiber waveguides composed of hole- and electron-transport materials, with a mean diameter of 480–660 nm were fabricated and their waveguiding properties studied. Dye emitted photoluminescence was guided in the fibers and the loss coefficient was calculated to be 1.2 × 10⁻³–3.9 × 10⁻³ μm⁻¹ at a wavelength of 540 nm, which is lower than previously reported for optically active polymer submicron fibers. Finally, a feasible method to couple the fibers with counter electrodes is presented using phase segregation of an insulating polymer. These submicron fiber waveguides, composed of optically and electrically active materials, can be used to produce OLED-waveguides, which are applicable in the fields of textile optoelectronics, lab-on-a-chip, and optogenetics.     

Design and control of a piezoelectric driven reticle assist device for prevention of reticle slip in lithography systems

This paper presents a device for managing the inertial loads on photoreticles of lithography scanners. At high scan accelerations, the reticle inertial load can approach the clamp force limit. As a result, nanometer-level presliding slip can occur. Reticle slip is one limitation on increasing the throughput of the lithography scanners. In this paper, we present a reticle assist device which can eliminate reticle slip by compensating better than 95% of the inertial loads when tested in a bench-top tester. The reticle assist device consists of a coarse approach mechanism, for accommodating reticle load/unload, and a piezoelectric stack for fine actuation. The device utilizes a sensorless control system design. The control system uses a self-sensing contact detection method, which is inspired by self-sensing scanning probe microscopy, to find the reticle edge. It also uses a charge amplifier with a novel hybrid hysteresis compensation technique to linearly control the piezoelectric actuator extension, without the need for closed-loop position control. When tested with a replicated force profile with 60 N peak force and 6400 N/s force rate, the assist device compensated better than 95% of the inertial load.     

Modelling and identification of the asymmetric hysteresis in the viscoelastic response of the fingertip under indentation: A multistate friction model with switching parameters

This paper presents a dynamic model for the identification of asymmetric hysteresis in the force response of the fingertip under cyclic local deformation of the fingertip soft tissues. Viscoelastic effects, marked anisotropy and nonlinearity contribute to the hysteretic behaviour of the force of the fingertip undergoing indentation. The fingertip force in response to an indentation stimulus varies along the loading and unloading cycles; the resulting hysteresis loops are asymmetric. The asymmetry arises from the simultaneous convexity of the branches of the hysteresis loop. The proposed model belongs to the class of multistate friction models that can effectively describe the hysteresis in the presliding regime of motion of general mechanisms with friction, by exploiting a mechanical analogy obtained through the concatenation of multiple elasto-plastic elements. The multistate model, which provides the mechanical representation of the fingertip response through a set of newly-conceived switching elements and viscoelastic blocks, can reproduce the convex and asymmetric hysteresis loops of the fingertip mechanical response, including the viscoelastic effects of stress relaxation and the influence of time interval between consecutive cycles of indentation.The model has been validated through the experimental identification of fingertip indentation tests performed on an optomechanical test-rig. This model potentially opens the way for efficient model-based control strategies of servomechanisms involved in tactile and haptic displays and interfaces.     

Maximal Delay Reduction for RLC-Based Multi-Source Multi-Sink Bus with Repeater Insertion

Signal propagation delay on a multi-source multi-sink bidirectional bus has a dominant effect on high-performance chips. This work presents a novel greedy algorithm that minimizes the critical propagation delay of an RLC-based bus. Based on the topology of a multi-source multi-sink bus and the RLC delay model, the proposed algorithm inserts signal repeaters into the critical path of the RLC-based bus and adjusts their sizes to minimize the maximal propagation delay. This procedure is repeated until no additional improvement is needed. Several buses with various topologies are tested using the proposed algorithm in deep submicron technologies. Experimentally, the critical delay in an RLC-based bus can be reduced dramatically by up to 62.4% with inserted repeater sizes of 24 and execution time of 1.65 s on average. Moreover, average delay reduction, repeater sizes, and running time for 0.18 μm technology are 5.8%, 6.4%, and 26.2%, respectively, better than those of 0.35 μm. Additionally, the topologies of all of the RLC-based buses with inserted repeaters in deep submicron technologies are simulated using HSPICE. The error ratio in the critical delay of a bus with inserted repeaters determined by comparison with HSPICE is 2.7% on average. The proposed algorithm is simple and extremely practical.     

Modeling and Identification of Elastic Robot Joints With Hysteresis and Backlash

This paper presents a novel approach to the modeling and identification of elastic robot joints with hysteresis and backlash. The model captures the dynamic behavior of a rigid robotic manipulator with elastic joints. The model includes electromechanical submodels of the motor and gear from which the relationship between the applied torque and the joint torsion is identified. The friction behavior in both presliding and sliding regimes is captured by generalized Maxwell-slip model. The hysteresis is described by a Preisach operator. The distributed model parameters are identified from experimental data obtained from internal system signals and external angular encoder mounted to the second joint of a 6-DOF industrial robot. The validity of the identified model is confirmed by the agreement of its prediction with independent experimental data not previously used for model identification. The obtained models open an avenue for future advanced high-precision control of robotic manipulator dynamics.     

Residue-free room temperature UV-nanoimprinting of submicron organic thin film transistors

In this study we report on an innovative nanoimprint process for the fabrication of entirely patterned submicron OTFTs in a bottom-gate configuration. The method is based on UV-Nanoimprint Lithography (UV-NIL) combined with a novel imprint resist whose outstanding chemical and physical properties are responsible for the excellent results in structure transfer. In combination with a pretreated stamp the UV-curable resist enables residue-free imprinting thus making etching obsolete. A subsequent lift-off can be done with water. The UV-NIL process implies no extra temperature budget, is time saving due to short curing times, eco-friendly due to a water-based lift-off, simple because it is etch-free and completely r2r compatible. It works perfectly even if ultra-thin organic and hybrid films are used as gate dielectrics. On this basis entirely patterned functional submicron OTFTs with pentacene as the semiconductor are fabricated showing clear saturation, low switch-on voltage (～3 V) and a sufficiently high on–off ratio (10³).     

Decentralized structure-integrated spatial force measurement in machine tools

New manufacturing processes and extended movability of modern machine tools, such as five-axis kinematics or hexapods, increase the demand for in-process measurement of spatial forces and torques in up to 6 degrees of freedom (DoF). The approach proposed in this paper is based on the idea of integrating 6 single-axis force sensors into the machine’s structure and converting these sensor forces to spatial forces and torques at the tool centre point (TCP) using a measurement model. This concept is advantageous to costs, ruggedness and available workspace when compared to state-of-the-art 6 DoF force/torque transducers. At the same time, the achievable measuring accuracy is similar and also significantly better than the accuracy of drive current based force evaluation. On the other hand, structure and machine influences have to be addressed by suitable measurement models. This article presents design, parametrization, verification, and characterisation of these measurement models on the example of four integration concepts, two in rigid bar frameworks and two in bar kinematics. Further, experimental results are shown which are classified in comparison to a 6 DoF F/T sensor and drive current based force measurement. Finally, other influences, such as structural design and deformations, as well as the integration of sensors and models into the machine’s control software are discussed.     

Facing the defect characterization and localization challenges of bridge defects on a submicronic technology (45 nm and below)

For very deep submicron technologies, 45 nm and less, bridge defects are getting more and more complex and critical. In order to find the exact root cause, accurate defect localization, precise understanding on the nature of the defect and its impact on the fine electrical behaviour of the device are mandatory. At these ultimate technologic nodes, failure analysis techniques show a real lack of efficiency on bridge defect localization while this precise location is one of the keys to find the defect root cause that allows correct implementation of corrective actions to improve yield and reliability.To face this challenge we have built a complete set of signatures related to advance Eldo simulations, performed measurement with ultimate failure analysis tools, fully characterized a microelectronic structure in advanced technology presenting a bridge defect and established a complete link between all these data and the failure location.     

LVI detection on passive structure in advance CMOS technology: New opportunities for device analysis

For very deep submicron technologies, 45 nm and below, Photoemission microscopy suffers from decreasing signal strength due to lower voltages. Laser Voltage Imaging (LVI) technique, introduced in 2009, allows mapping frequency through the backside of integrated circuit. For 1340 nm laser wavelength, the measured reflected signal is related to charge carrier density modulation. This signal is measured on active areas at transistor level. In this paper we discuss about the LVI (Laser Voltage Imaging) signal observed on passive structures such as copper and polysilicon resistors. We describe the way to use the LVI technique, usually dedicated to frequency mapping of digital active parts, for the location of resistive leakage. The origin of this signal is investigated including charge carrier density variations and thermo reflectance effect. Experimental results on 45 nm technology are presented. We show that the ability to perform ‘LVI’ measurements on passive structures “open the door” for the characterization of deep submicron devices.     

Blocage par injection de modes sous- harmoniques d’un oscillateur utilisant une ligne à retard à ondes de surface

A nonlinear regeneration pulsed oscillator driven by a monochromatic source has been built. Subharmonics of the resonance carrier/modulation are measured with an accuracy of 10^-10 thanks to the use of a double beats measurement set-up. The multiscale analysis of frequency readings reveals a rich fine structure which is in agreement with the nonlinear topological approach of synchronized states.     

Multiscale Construction of Bifunctional Electrocatalysts for Long‐Lifespan Rechargeable Zinc–Air Batteries

Zinc–air batteries deliver great potential as emerging energy storage systems but suffer from sluggish kinetics of the cathode oxygen redox reactions that render unsatisfactory cycling lifespan. The exploration on bifunctional electrocatalysts for oxygen reduction and evolution constitutes a key solution, where rational design strategies to integrate various active sites into a high‐performance air cathode remain insufficient. Herein, a multiscale construction strategy is proposed to rationally direct the fabrication of bifunctional oxygen electrocatalysts for long‐lifespan rechargeable zinc–air batteries. NiFe layered double hydroxides and cobalt coordinated framework porphyrin are selected as the active sites considering their high intrinsic activity at the molecular level, and the active sites are successively integrated on three‐dimensional conductive scaffolds at mesoscale to strengthen ion transportation. Consequently, the multiscale constructed electrocatalyst exhibits excellent bifunctional performance (ΔE = 0.68 V), which is even better than that of the noble metal based benchmarks. The corresponding air cathodes endow zinc–air batteries with a reduced voltage gap of 0.74 V, a high power density of 185.0 mW cm^?2, and an ultralong lifespan of more than 2400 cycles at 5.0 mA cm^?2. This work demonstrates a feasible strategy to rationally integrate various active sites to construct multifunctional electrocatalysts for energy‐related processes.     

A 6-bit 2.5-GS/s flash ADC using comparator redundancy for low power in 90 nm CMOS

A 2.5 GS/s flash ADC, fabricated in 90 nm CMOS utilizes comparator redundancy to avoid traditional power, speed and accuracy trade-offs. The redundancy removes the need to control comparator offsets, allowing the large process-variation induced mismatch of small devices in nanometer technologies. This enables the use of small-sized, ultra-low-power comparators with clock-gating capabilities in order to reduce the power dissipation. The chosen calibration method enables an overall low-power solution and measurement results show that the ADC dissipates 30 mW at 1.2 V. With 63 comparators, the ADC achieves 3.9 effective number of bits.     

高精度轴对称非球面反射镜轮廓测量方法（特邀）

为实现轴对称非球面反射镜轮廓的高精度、可溯源测量,建立了非球面测量轨迹的数学模型,提出了一种基于独立计量回路的非接触式坐标扫描测量方法。该方法采用分离式计量框架结构,有效减少了跟踪扫描模块运动对测量精度的影响;测头采用集成阵列式波片的四象限干涉测量系统,保证测头精度的同时更有利于实现复杂面形轮廓的跟踪扫描运动;设计扫描执行机构与多路激光干涉系统共基准的运动模块,实时跟踪扫描运动机构的位置信息,提高测头空间定位精度并使其测量值能溯源到“米”定义。搭建测量装置测试该方法的准确测量精度,试验结果表明,测量误差小于0.2 μm,重复性精度为70 nm,测量精度达到亚微米级。     

Design and Realization of a Built-In Current Sensor for IDDQ Testing and Power Dissipation Measurement

Built-in current sensor (BICS) is known to enhance test accuracy, defect coverage of quiescent current (I_DDQ) testing method in CMOS VLSI circuits. For new deep-submicron technologies, BICSs become essential for accurate and practical I_DDQ testing. This paper presents a new BICS suitable for power dissipation measurement and I_DDQ testing. Although the BICS presented in this paper is dedicated to submicron technologies that require reduced supply voltage, it can also be used for applications and technologies requiring normal supply voltage. The proposed BICS has been extended for on-line measurement of the power dissipation using only an additional capacitor. Power dissipation measurement is important for safety-critical applications and battery-powered systems. A simple self-test approach to verify the functionality and accuracy of BICSs has also been introduced. The proposed BICS has been implemented and tested using an N-well CMOS 1.2 m technology. Practical results demonstrate that a very good measurement accuracy can be achieved.     

An analytical model with flexible accuracy for deep submicron DCVSL cells

Differential cascoded voltage switch logic (DCVSL) cells are among the best candidates of circuit designers for a wide range of applications due to advantages such as low input capacitance, high switching speed, small area and noise-immunity; nevertheless, a proper model has not yet been developed to analyse them. This paper analyses deep submicron DCVSL cells based on a flexible accuracy-simplicity trade-off including the following key features: (1) the model is capable of producing closed-form expressions with an acceptable accuracy; (2) model equations can be solved numerically to offer higher accuracy; (3) the short-circuit currents occurring in high-low/low-high transitions are accounted in analysis and (4) the changes in the operating modes of transistors during transitions together with an efficient submicron I-V model, which incorporates the most important non-ideal short-channel effects, are considered. The accuracy of the proposed model is validated in IBM 0.13 µm CMOS technology through comparisons with the accurate physically based BSIM3 model. The maximum error caused by analytical solutions is below 10%, while this amount is below 7% for numerical solutions.     

Multifunctional and Wearable Patches Based on Flexible Piezoelectric Acoustics for Integrated Sensing,Localization, and Underwater Communication

Flexible and wearable sensors are highly desired for health monitoring, agriculture, sport, and indoor positioning systems applications. However, the currently developed wireless wearable sensors, which are communicated through radio signals, can only provide limited positioning accuracy and are often ineffective in underwater conditions. In this paper, a wireless platform based on flexible piezoelectric acoustics is developed with multiple functions of sensing, communication, and positioning. Under a high frequency (≈13 MHz) stimulation, Lamb waves are generated for respiratory monitoring. Whereas under low-frequency stimulation (≈20 kHz), this device is agitated as a vibrating membrane, which can be implemented for communication and positioning applications. Indoor communication is demonstrated within 2.8 m at 200 bps or 4.2 m at 25 bps. In combination with the sensing function, real-time respiratory monitoring and wireless communication are achieved simultaneously. The distance measurement is achieved based on the phase differences of transmitted and received acoustic signals within a range of 100 cm, with a maximum error of 3 cm. This study offers new insights into the communication and positioning applications using flexible acoustic wave devices, which are promising for wireless and wearable sensor networks.     

Coriolis mass-flow meter with integrated multi-DOF active vibration isolation

Vibration isolation of more than 40 dB is achieved for a Coriolis Mass-Flow Meter (CMFM) with integrated Active Vibration Isolation. A CMFM is an active device based on the Coriolis force principle for direct mass-flow measurements independent of fluid properties. The mass-flow measurement is derived from tube displacement measurements. Support excitations can introduce motions that cannot be distinguished from the Coriolis force induced motion, thus introducing a measurement error. Therefore, the measurement stage is passively suspended at 30 Hz in the 3 out-of-plane directions. Active vibration isolation is added to increase the attenuation. In this paper the system model and controller design are presented. Based on the model an on-scale proof of principle is built and the model and controller are validated in multi-DOF. Acceleration feedback and a novel adaptive feedforward control strategy are compared A filtered-reference least-mean-square (FxLMS) adaptive scheme is used to determine the optimal feedforward controller parameters to minimise a squared error signal; the motion of the measurement stage. Both strategies result in an attenuation of 10 – 20 dB at 175 Hz in addition to the 30 dB attenuation obtained by the 30 Hz passive vibration isolation stage. The performance of the feedback strategy is limited by robust stability and the the feedforward performance is limited by sensor noise.