PZT Driver Research Articles

A method to estimate the transient fluid pressure of a piezoelectric inkjet printer using system dynamic analysis

PurposeThis paper aims to present a method based on dynamics to find the transient pressure at the nozzle area of a piezoelectric inkjet printer. This pressure responds to input signals of the piezoelectric driver deformation. The pressure at the nozzle is the boundary condition of the computational fluid dynamics model of the inkjet printer nozzle, and serves as the “bridge” between the piezoelectric driver actuation and the droplet generation of an inkjet printer.Design/methodology/approachThe transient pressure was estimated using a fluid-solid coupling numerical model of the printerhead. In this study, a simple step-shape signal was applied. The printerhead chamber was considered to act as a linear Helmholtz resonator to determine the system transfer function between the input of driver deformation and the output of pressure. By decomposing the input signal into several simple signals, the transient pressure is the superposition of those calculated pressures.FindingsThe pressure values determined by transfer function and by superposition match the pressure values directly calculated by a fluid-solid coupling model. This demonstrates the rationality and practicability of the method.Originality/valueThis paper proposes a method to identify a proper boundary condition of pressure for numerical models that only include the fluid field around the nozzle. This strategy eliminates the need to calculate the complex and unstable fluid-solid coupling for every pattern of input. Additionally, the suitable boundary condition of transient pressure can be set rather than relying on the shape of the PZT driver deformation signal.

Single‐/Dual‐FBG‐based gain controller of gain‐clamped L‐band erbium‐doped fiber amplifier with high gain and flatness

ABSTRACTIn this letter, we report a novel fiber Bragg grating (FBG)‐based gain controller to simultaneously flatten and clamp the gain spectrum of a long‐wavelength‐band (L‐band) erbium‐doped fiber amplifier (EDFA). Respectively, the single‐ and dual‐FBG schemes are experimentally conducted and investigated in terms of flatness and dynamic stability with various central wavelengths. The results show that, under a suitable central wavelength of FBGs, the high average gain (over 22 dB) and ±0.1 dB stability in ∼30 dBm dynamic range is together guaranteed in our designed amplifier. In gain‐flatness, dual‐FBG scheme presents a smaller fluctuation (∼0.93 dB) in the range of 1570–1610 nm by accurately adjusting the voltage of PZT driver. Comparatively, single‐FBG scheme is more practical and controls the gain‐fluctuation of EDFA below 1.62 dB in the whole L‐band. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2168–2171, 2016

光刻物镜中压电陶瓷驱动器的动态性能研究

The dynamic performance of a PZT driver which contains an operational amplifier was studied according to the specific requirements of the image quality compensator in a lithographic objective.Firstly,the impact of the inherent frequency characteristics of the operational amplifier on dynamic performance was analyzed and the parameters of the compensatory network were fixed.Secondly,the impact of the capacitive load of the driver system on dynamic performance was analyzed and the corresponding solution was provided.Finally,the impact of the parasitic capacitance in the driver system was discussed.As calculated,after compensated the PZT driver system had a phase margin of 79 degrees and a setting time of 5 microseconds,and presented no overshoot in step response.The driver would fulfill the dynamic requirements of strong stability,rapid response and little overshoot when the PZT was used as actuator of the image quality compensator in a lithographic objective.

2A1-D11 三方向振動駆動式無拘束ポペット空気圧弁の製作(アクチュエータの機構と制御(1))

In this paper, we describe 3-way unconstrained vibrational pneumatic poppet valves. Wearable robots need many pneumatic valves to drive McKibben actuators. Thus, it is important to miniaturize these valves. We develop unconstrained vibrational pneumatic poppet valves with PZT drivers. We need supply and exhaust valves to drive one MaKibben actuators. In this paper, two valves were integrated for one actuator. Experiment showed that our 3-way valves could supply enough flow rates. We check the flow rate for various cases of the exhaust valve. Additionally, we check the influence between the supply base and exhaust case by sandwiching the tube between two valves.

2A2-C12 振動駆動式無拘束ポペット空気圧弁のための駆動回路の小型化

In this paper, we describe the miniaturization of PZT driver circuits for unconstrained vibrational pneumatic poppet valves. In recent years, we need the valve enough to drive the McKibben actuator for robots. It is important to make drivers for the valves small. We have developed small valves, but our valves need PZT driver circuit. This PZT drivers need to output high voltage square or sine wave for the piezoelectric actuator in the valve because their flow-rate depend on the displacement of the actuator and this displacement depends on the input voltage. As PZT driver components, we apply push-pull circuits with MOS-FETs and LC circuits with coils. The former can output higher voltage depending on MOS-FET's specifications. It is easy to make them smaller because of their simple structure. The latter use coils and it is easy to increase the output voltage to 25 through 100V from 10V input.

Effect of ultrasonic power on the wire bonding strength

The PZT driver signal during bonding process and the shear test force of the corresponding wire bonding point are acquired as the indicator of ultrasonic power and bonding strength respectively in the large aluminum wire wedge bond- ing experiments.The bonding force,temperature and time are 4.7 N,room temperature and 100 ms respectively,which are selected according to industrial practice.The effect of ultrasonic power on large aluminum wire wedge bonding strength is stud- ied by changing the ultrasonic power rate,which is defined as the rate between set and maximum ultrasonic power.1 000 times bonding experiments in 20 groups are done,with 20 kinds ultrasonic power rate set between 15%～100%.Correlation be- tween the ultrasonic power and the bonding strength is found. When ultrasonic power is less then 1.0 W,the bonding strength will increase with the power increase while the fail bonding will decrease,and the opposite will happen when ultrasonic power is larger than 1.6 W.Only when ultrasonic power is between 1.0 W and 1.6 W,can stable and high yield bonding be reached. And when larger then 3.5 W,there are no obvious rules. Moreover,ultrasonic power is effect by ultrasonic power ratio and other uncontrolled factors such substrate quality,restricts between tool and wire,and so on.

A miniaturized micro-machined thermoacoustic cooler

A thermoacoustic cooler of miniature scale with a micro-machined stack has been numerically modeled and experimentally realized. deltae and Fluent were used to perform the numerical modeling and simulation. The acoustic pressure, velocity, and temperature profiles in the stack and exchangers were simulated. The stack is manufactured using MEMS technology for precise dimension control and flexible geometry design. The MEMS stack as thick as 4.2 mm with high aspect ratio (1/50) thin rib structures, 10 to 15 μm, have been realized. Commercially available PZT drivers were initially used to deliver acoustic power into the resonator at around 4 kHz. A more powerful acoustic driver design using PLZT is under development. The simulation result, device performance, and system integration will be reported. [Work supported by DARPA.]

New synthetic-heterodyne demodulator for an optical fiber interferometer

A new algorithm for modulating a PZT stack using a sinewave signal instead of a saw-tooth signal was developed in order to resolve the flyback problem in a PZT driver. An improved synthetic heterodyne demodulator circuit was designed and arranged to interrogate the output signal from an interferometric sensor with a sinewave modulation (phase-generated carrier). The depth of modulation, or a gain amplifier in the circuit design, was adjusted such that the standard heterodyne signal could be formed. The result is a conventional PM-modulated carrier that can be demodulated using standard techniques, followed by a lock-in amplifier or a phase meter, to recover the phase shift in the sensing information. Implementing it into a path-matching differential interferometer for the signal modulation validates this new method. As compared to the conventional technique, modulating the PZT stack in a saw-tooth signal, this technique supplies a wider modulated frequency and, therefore, a wider frequency response in a sensing system. Finally, the new synthetic heterodyne is applied to a differential optical fiber refractometer for measuring the refractive index change. A lock-in amplifier is chosen as the demodulator to extract the phase shift. Therefore, the resolution of this sensing system is 7.52/spl times/10/sup -7/ refractive index unit for a 120-/spl mu/m length of the sensing cavity.

UHV compatible compact double-crystal monochromator at BEPC diffraction and scattering beamline 4B9A

A UHV compatible compact double-crystal monochromator was designed and constructed for BEPC diffraction and the scattering beamline 4B9A. It is a compact device with a 325 ×250×250 mm3 vacuum chamber. A T-structure mechanism has been designed for allowing the monochromator to have a Bragg angle range from 5° to 70° and keep the exit beam position and direction fixed during wavelength tuning. The first crystal is cooled by a heat-pipe cooling system and a pair of PZT drivers provide a two-dimensional adjustment to optimize the alignment between two crystals. The design and operating principles are described in this paper.

Relationship of ossicular chain displacement and CM resulting from stimulation with direct contact piezoelectric drivers

Frequency-response curves (300 Hz–10 kHz) relating displacement of PZT driver assembly tip when driving the ossicular chain of anesthetized guinea pigs at the umbo and resulting CM were obtained. These measures were compared with similar measures of umbo displacement, CM and SPL obtained when the tympanic membrane of the same animals were driven in the normal acoustical manner. The effect on CM of driving different parts of the ossicular chain were compared as well as displacement of the umbo when the incudo-stapedal joint is driven. Displacements delivered to the incus just behind the incudo-stapedal joint were found to produce on the order of 10 dB greater CM than equal displacement delivered at the umbo. The apparent necessity for an ossicular chain “DC” offset for production of maximum CM at a specific displacement level when using direct ossicular chain contact methodologies is discussed. Oscilloscopic displays of PZT driver tip displacement pattern for complex waveforms and resulting CM are shown.