A5067632579- Advanced MEMS and NEMS Technologies
- Mechanical and Optical Resonators
- Acoustic Wave Resonator Technologies
- Magnetic Field Sensors Techniques
- Force Microscopy Techniques and Applications
- Advanced Fiber Optic Sensors
- Geophysics and Sensor Technology
- Photonic and Optical Devices
- Advanced machining processes and optimization
- Flexible and Reconfigurable Manufacturing Systems
- Electronic and Structural Properties of Oxides
- Inertial Sensor and Navigation
- Injection Molding Process and Properties
- Magnetic properties of thin films
- Advanced Sensor and Energy Harvesting Materials
- Interactive and Immersive Displays
- Tactile and Sensory Interactions
- Non-Invasive Vital Sign Monitoring
- Healthcare Technology and Patient Monitoring
- Electrowetting and Microfluidic Technologies
- ECG Monitoring and Analysis
University of Minho
2014-2020
International Iberian Nanotechnology Laboratory
2018-2020
This work presents a flexible polyimide-based capacitive tactile sensing array with sub-millimeter spatial resolution. The sensor is conceived to be embedded in multimodal artificial finger detect and classify the texture morphology of an object's surface. proposed comprises 16 × units. Each unit composed parallel square electrode pairs (340 μm 340 μm) separated by compressible air cavity into polyimide substrate. Standard MEMS microfabrication techniques were used develop sensor. device was...
Several devices and measurement approaches have recently been developed to perform ballistocardiogram (BCG) seismocardiogram (SCG) measurements. The development of a wireless acquisition system (hardware software), incorporating novel high-resolution micro-electro-mechanical (MEMS) accelerometer for SCG BCG signals data treatment is presented in this paper. A small accelerometer, with sensitivity up 0.164 µs/µg noise density below 6.5 µg/ Hz used applications. also incorporates...
Predictive maintenance has been growing as one of the main topics Industry 4.0 concept and several challenges arise from it. The constant search for mechanisms that allow control reduction machine down-time led to study new ways extracting valuable information injection tools through monitorization different parameters. In presented here, a custom pressure sensor is integrated into an tool monitor levels along process cycle, together with commercial off-the-shelf accelerometer, coupled at...
Here, a frequency modulated MEMS accelerometer encapsulated in vacuum is presented. The small size (0.25 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) and the capability of encapsulation at low pressures (≈ 150 Pa) are main advantages reported. A high sensitivity (85 Hz/g) for single double-ended tuning fork (DETF) resonator achieved due to addition force amplification mechanism, fully optimized through finite-element method...
A very high-resolution SOI (silicon-on-insulator) MEMS (Micro-Electro-Mechanical Systems) accelerometer for geodetic space grade applications using pull-in time measurements is presented here. Parallelplates implemented in the handle-layer are used to provide necessary squeeze-film damping, while increasing effective-mass. Large mass (126 mg) devices with low-Q (quality factor of 0.53) have been fabricated and tested transduction. The high measured sensitivity 1.9 ns/ng enables use device...
In this paper, we present a bi-directional extended range parallel-plate electrostatic actuator using feedback linearization control. The can have stable displacements up to 90% of the full-gap (limited by mechanical stoppers) on both directions, i.e., device move ±2μm within ±2.25μm gap. system has successfully tracked references until 1kHz dynamics device) and it presents capacitor tuning 17, an actuation voltage from 0 10V. results presented here are clear advance in respect current...
A low-voltage, high-tuning range variable MEMS capacitor using parallel-plates electrostatic microactuators operated in close-loop is introduced this paper. The structures were fabricated an in-house 2-masks process on SOI wafers and the use of a closed-loop controller increases stable displacements structure beyond pull-in limitation along full available gap (the are mechanical stoppers). Additionally, has two pairs actuators, opposing directions, enabling bi-directional displacement...
A Lorentz force MEMS magnetometer based on a double-ended tuning fork (DETF) for out-of-plane sensing is presented here. novel configuration using hexagonal-shaped transducer used, which simplifies the sensor and improves its sensitivity. Frequency modulated devices were fabricated in an in-house process silicon insulator wafers (SOI) then tested vacuum. The final have differential experimental characterization shows sensitivity of 4.59 Hz/mT total input current (on bar) 1.5 mA.
Resonant accelerometers are an alternative to amplitude modulated devices due their higher integration capabilities, since they encapsulated in vacuum and stable at low pressures. Vacuum is required for some sensors (i.e., gyroscopes) but tend be unstable under such conditions therefore cannot integrated the same package. Herewith, a device composed by double-ended tuning fork resonators (DETF) force amplification mechanism sensitivity enhancement presented. Characterization of fabricated...
This paper reports a MEMS magnetometer with geometrical improvements to increase the displacement resulting from Lorentz forces. It relies on lever-like suspension springs which present over tenfold lower electrical resistance (thus allowing higher currents) than conventional guided-beam same compliance. By combining multiple force generating bars and off-resonance operation in vacuum (1 mbar), these devices can yield: noise of 2.65 nT/√Hz (theoretical) bias current 4 mA each 6 (63.6...
Frequency modulated accelerometers composed of two double-ended tuning fork (DETF) resonators on a differential configuration were characterized for their sensitivity to force applied package. Commonly, architectures are employed cancel common-mode errors, such as the mechanical stress or temperature dependency. The device dependence was experimentally measured forces up 15 N and reduction about 5.6 times obtained measurement. Additionally, silicon dies glued chip-carriers using different...
An approach aiming bidirectional full-gap tracking of parallel-plate electrostatic microactuators is presented here. The based on an On-Off control law, manipulating the structure location by actuating or releasing device if actual greater smaller than reference desired position. existing ripple due to delays readout circuit and circuitry. In order minimize part, a high sampling frequency, 5 MHz, used. Experimental results show signals up 100 Hz extended travel range 88.9% full available gap...
This digest reports for the first time on concept, fabrication and characterization of a spintronics magnetic readout hybrid MEMS. The method uses sensors (spin valves) permanent magnets (on both movable fixed parts MEMS structure) to detect displacement. use such transduction has several potential advantages: it allows small form factor, straightforward electronics, xyz integrability, does not require high aspect ratio silicon gaps, allowing replacement conventional capacitive transductors...