Enhancing the thermal responsivity of microelectromechanical system beam resonators by preloading a critical buckling strain

In this study, a multi-function microelectromechanical system (MEMS) was integrated with a MEMS oscillator, using the resonant frequency oscillation characteristics of the oscillator to provide the Lorentz current of the magnetometer to enhance a large dynamic range of reading, which eliminates the off-chip clock and current generator. The resonant frequency can be adjusted by adjusting the bias voltage of the oscillator to further adjust the sensitivity of the magnetometer. With the mechanical Q value characteristic, a great dynamic range can be achieved. In addition, using the readout circuit of the nested chopper and correlated double-sampling (CDS) to reduce the noise and achieve a smaller resolution, the calibration circuit compensates for errors caused by the manufacturing process. The frequency of the tuning range of the proposed structure is 17,720–19,924 Hz, and the tuning range of the measurement result is 110,620.36 ppm. The sensitivities of the x-, y-, and z-axes of the magnetometer with driving current of 2 mA are 218.3, 74.33, and 7.5 μV/μT for ambient pressure of 760 torr. The resolutions of the x-, y-, and z-axes of the magnetometer with driving current of 2 mA are 3.302, 9.69, and 96 nT/√Hz for ambient pressure of 760 torr.

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Application of the MEMS Accelerometer as the Position Sensor in Linear Electrohydraulic Drive

Sensors ◽

10.3390/s21041479 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1479 ◽

Cited By ~ 1

Author(s):

Dominik Rybarczyk

Keyword(s):

High Price ◽

Second Phase ◽

Position Sensor ◽

Microelectromechanical System ◽

Mems Accelerometer ◽

Drive Control ◽

Electrohydraulic Drive ◽

Preliminary Research ◽

Two Phases ◽

Correction Phase

Various distance sensors are used as measuring elements for positioning linear electrohydraulic drives. The most common are magnetostrictive transducers or linear variable differential transformer (LVDT) sensors mounted inside the cylinder. The displacement of the actuator’s piston rod is proportional to the change in the value of the current or voltage at the output from the sensor. They are characterized by relatively low measurement noise. The disadvantage of presented sensors is the need to mount them inside the cylinders and the high price. The article presents preliminary research on the replacement of following sensors and the use of a microelectromechanical system (MEMS) accelerometer as a measuring element in the electrohydraulic drive control system. The control consisted of two phases: at first, the signal from the acceleration sensor was analyzed during the actuator movement, based on the value determined from the simplified model implemented on the controller. In the range of motion in which the dynamics were the lowest, the signal was integrated and the obtained value was used in the second phase of motion. In the correction phase, a new set point was determined. Conducting the research required building a dedicated research stand. The author conducted the simulation and experimental research.

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Microactuator based on electroplated permanent magnets and flexible polydimethyl siloxane diaphragm

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes596 ◽

2008 ◽

Vol 222 (3) ◽

pp. 517-524 ◽

Cited By ~ 2

Author(s):

Y Su ◽

H Wang ◽

W Chen

Keyword(s):

Permanent Magnets ◽

Magnetic Energy ◽

Optical Switch ◽

Geometrical Parameters ◽

Maximum Deflection ◽

Polydimethyl Siloxane ◽

Flexible Membrane ◽

Microelectromechanical System ◽

Planar Coil ◽

A Current

The design, fabrication, and testing of a novel bidirectional magnetic microactuator were presented in the paper. The microactuator is composed of an integrated planar coil and a flexible polydimethyl siloxane (PDMS) diaphragm with embedded CoNiMnP-based permanent magnet arrays. There is a 7 × 7 array of magnets in a unit. The PDMS diaphragm is 2 mm × mm × 40 μm and the magnet post is 50 × 50 × 20 μm. Computer simulation was applied to verify the geometrical parameters. Electroplating under external magnetic field is carried out to improve the magnetic properties of the electroplated magnet, including coercivity, remanence and magnetic energy, and so on. The measured maximum coercivity, remanence and maximum magnetic energy were 2623 Oe (208.73 kA/m), 0.2 T (2000 G), and 10.15 kJ/m3 with the magnetic post, respectively. Moreover, and the deflection of the PDMS membrane is proportional to the exciting current. In a case of 0.35 A current, the maximum deflection of the membrane is 45 μm. Adjusting the electroplating mould results in the variation of the electroplated structure, thus the calibration of the microactuator. Due to the biomedical compatibility and simplicity of the fabrication, the flexible membrane-based microactuator is potential to be used as micropump and optical switch, the microelectromechanical system applications.

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