Improvement of Tuning Fork Gyroscope Drive-mode Oscillation Matched using a Differential Driving Suspension Frame

This paper presents a novel design of a vibration tuning fork gyroscope (TFG) based on a differential driving suspension coupling spring between two gyroscopes. The proposed TFG is equivalent to a transistor differential amplifier circuit. The mechanical vibrations of driving frames are, therefore, well matched. The matching level depends on stiffness of spring. When three various TFG structures respond to differential stiffness of spring, their the driving frame mechanical vibration is well matched in case the input excitation driving differential phase is less than 3.5°, 2.5°, and 4°, respectively. The fabricated tuning fork gyroscope linearly operates in the range from -200 to +200 degree/s with the resolution of about 0.45 mV/degree/s

Mechanical response of outer frames in tuning fork gyroscope model with connecting diamond-shaped frame

In tuning fork micro-gyroscopes, two outer frames are connected by using the linking elements. The driving vibrations of the two outer frames are required to be exactly opposite to generate the opposite sensing modes perpendicular to driving direction. These opposite driving vibrations are provided by a mechanical structure named the diamond-shaped frame. This paper presents mechanical responses of two outer frames in a proposed model of tuning fork gyroscope when an external force with different types is applied to them. The results show that the presence of a diamond-shaped frame guarantees the absolute anti-phase mode for the driving vibrations of outer frames

Attenuation coefficient for surface acoustic waves in fluid region

In recent years, surface acoustic wave devices used in bio-sensing applications have demonstrated high sensitivity in the detection of fluid properties such as density, viscosity, stream velocity. In this paper, a more effective measurement of the SAWsensorstructure is presented. It is reported that at density of 6 g/cm3, the amplitude of mechanical wave is excited while for electrical signal, attenuation at 3 g/cm3 reaches a peak.In our analysis, single–crystal Aluminium Nitride substrate is used. Several parameters of leaky waves including displacement, decay constant in the liquid media are analyzed

A study of ion wind generator using parallel arranged electrode configuration for centrifugal flow mixer

Ion wind is recently applied in various research areas such as the biomedical engineering, microfluidic mixing and particle manipulation. In this work, a bipolar ion wind generator configured by parallel arranged electrodes is used for centrifugal mixing applications. With the proposed configuration, negative and positive ion winds are simultaneously generated, mixed and then neutralized by each other while travelling toward liquid surface. The efficiency of the device was investigated both computationally and experimentally. The mixing of liquid occurred in different ways when the system is activated by either direct or alternating currents. Furthermore, the mixing is dependent on the dimension of electrode tip

A circulatory ionic wind for inertial sensing application

A novel gyroscope using circulatory electro-hydrodynamics flow in a confined space is presented for the first time. The configuration of the new gyroscope includes three point-ring corona discharge actuators that generate ion flows in three separated sub-channels. The three ion flows then merge together when going through a nozzle of the main chamber entrance and create a jet flow. In the new configuration, the residual charge of ion wind flow is removed by a master-ring electrode located at one end of the main chamber. Under the effect of the angular speed of gyroscope, the jet flow is deflected and this deflection is sensed using hotwires. The results, which are consistently acquired by both the numerical simulation and experiment on our prototypes, demonstrate the repeatability and stability of the new approach. Since the ion wind can be generated by a minimum power, the present configuration-based device does not require any vibrating component. Thus, the device is robust, cost, and energy-effective

Angular rate sensing by circulatory vortex flow: design, simulation and experiment

A fully packaged convective vortex gyrometer actuated by a PZT diaphragm is reported. The flow circulates at higher velocity after each actuating circle to form a vortex in the desired chamber. The vortex is characterized by hotwire anemometry. The device is initially designed based on a numerical analysis whose results are used to set up the experiment. The angular rate sensing of the device is successfully tested using a turntable. The technique is a potential solution to various applications related to inertial sensing and fluidic amplifier

Simulation and optimization of a silicon-polymer bimorph microgripper

This paper presents an electro-thermally bimorph microgripper based on silicon-polymer laterally stacked structures and a method to optimized the fabricated device. The actuated displacement is enhanced due to the polymer constraint effect. Both the thermal expansion and apparent Young’s modulus of the constrained polymer blocks are significantly improved, compared with the no constraint one. The device consists of a serpentine-shape deep silicon structure with a thin film aluminum heater on the top and filling polymer in the trenches among the vertical silicon parts. The fabricated bimorph microgripper can operate in four modes and generates a large motion up to 15 μm. The simulated results are met the fabricated measurements. An optimized structure is proposed for decreasing the working temperature, power consumption but increasing the output displacement. The simulated results are showed that the output displacement is increased up to 550% and temperature profile improved considerably. This electro-thermally silicon-polymer opened and closed microgripper can be used in micro-robotics, micro-assembly, minimally invasive surgery, living cells surgery.

Computational and experimental study on ion wind scheme based aerosol sampling for biomedical applications

In this paper, an efficient electrostatic particle sampling system is developed based on the neutralized ion wind. Compare with the conventional schemes where unipolar ion is used to charge the airborne sample and the sampling stage is fixed as a part of high voltage circuit, the new approach allows sampling stage to be electrically floated and adds insignificant charge to the bioaerosol, thus reduces damages to the microorganisms while provides design flexibility and good collecting efficiency. The approach is suitable for the combination with a microfluidic interface to develop complex aerosol-tohydrosol bio-samplers

Study on point-to-ring corona based gyroscope

We present for the first time a novel gyroscope using circulatory electro-hydrodynamics flow in a confined space. Three point-ring corona actuator is to generate ionic flows in three separated channels and the ionic flows then merge together at a nozzle of the main chamber to create a jet flow. The residual charge of ion winds is removed by a master-ring electrode. By the effect of angular rate, the jet flow handled by a hotwire anemometry is deflected and sensed. Results by both experiment and numerical simulation consistently show good repeatability and stability of the new configuration-based device. Since ion wind is generated by a minimum power, the device does not require any vibrating component, thus the device is robust, low cost and energy consumption