Contact Position Microsensors with Travel Ranges between 50μm and 2mm (original) (raw)
A New Contact-Type Displacement Sensor for Nano-Positioning Systems
A new capacitive displacement sensor is designed and fabricated for measurement of a large displacement with very high accuracy. This sensor is a kind of linear encoder with an array of micro electrodes made by micromachining processes. The two patterned electrodes on the sensor substrates are assembled facing each other after being coated with thin dielectric film. Due to the thin dielectric film, it is highly sensitive to displacement but minimizes expected misalignments such as a tilting error. The sensor fabricated as a sample has a grating of electrodes with a width of 100µm, which is coated with a Diamond-Like Carbon(DLC) film 0.8 µm thick. The proposed sensor was tested to conclude that its resolution is 9.07 nanometers for the measuring range of 15 millimeters and that the linearity error is expected to be less than 0.02% throughout the measurable range.
Low-Cost Contact Angle Measurement System for QCM Sensor
TELKOMNIKA (Telecommunication Computing Electronics and Control)
Hydrophobicity is one of the importance factors in the surface properties of materials. This work presents the development of a low-cost contact angle measurement system based on goniometric measurement using an inexpensive digital camera, tilt control system for surface alignment and curvature approximation algorithm to determine the contact angle between the solid and spherical cap of a water droplet. The design is specifically targeted for measuring the contact angle of a Quartz Crystal Microbalance sensor in the form of HC-49/U with a disc diameter of 8.7mm.The contact angle measurement using goniometric measurement depends on the quality of captured image and calculation method for the angle determination. Proper alignment of the sample surface is required to minimize the discrepancy of the angle measurement of water drop surface profile caused by gravity. A PIC18F4550 microcontroller is used to control the motorized tilt platform to reduce the gap between left and right contact angle value. Circle fit algorithm to determine the contact angle value from the captured image is used. Using the motorized tilt control system and circle fit algorithm, the developed contact angle measurement system able to measure the contact angle with discrepancy less than 1 O .
This paper reports on the development of a piezoresistive microcantilever sensor read-out circuitry to detect acceleration, biological or chemical activities. Laser micromachining technique is used in fabricating the piezoresistive microcantilever sensor as well as assisting in the cantilever beam and piezoresistor shape formation. In order to test the sensor performance, a Wheatstone bridge which acts as resistive sensor is integrated with three other resistors and the fabricated sensor. A set of amplifier circuit consisting of INA128 is developed to amplify and extract the electrical signal component of the bridge circuit. The resistance and output voltage characteristic of the Wheatstone bridge is investigated, where the percentages difference between the calculated and measured output voltage is very low and similar to each other. The sensor response to vibration is also studied using an electro-dynamic vibration system. The system is designed specifically to enable the accessibility of a small resistivity change due to outside reaction.
Embedded Devices and Methods for Development of Special Non-Contact Applications
Journal of Engineering Science, 2024
There are applications which require particular approaches for each of the used parts. The non-contact strain sensors based on microwires with positive magnetostriction requires specific technological processes starting from casting until development of the corresponding non-contact sensor device. The developed contactless sensors can be embedded into various industry critical parts which require continuous monitoring and maintenance. Hence, specific embedded devices and specific framework should be developed to provide industry reliable solution. The paper describes the technological process of casting microwires, methods of improvement casting process and stress annealing methodology used to obtain appropriate non-contact sensible elements based on microwires. Also, the paper describes the framework of using these elements in non-contact monitoring applications of the condition of specific engineering objects/structures.
Development of specifications for an integrated piezoelectric wafer active sensors system
Smart Structures and Materials 2005: Smart Structures and Integrated Systems, 2005
This paper describes work performed in the development of a set of specification for the construction of an integrated electronic system for piezoelectric wafer active sensor (PWAS). The paper starts with a comprehensive review of the PWAS material properties, dimensions, and electrical characteristics. PWAS of various shapes and sizes are considered. Two boundary conditions were examined: free PWAS and PWAS attached to actual structures. For both, the PWAS immittance and the allowable dc and ac voltages were considered. The predicted values were compared with measurements performed over a wide frequency range (10 kHz to 2 MHz). Next, the electronic-equipment specifications were considered. The PWAS can be used in a number of different ways to actively detect damage in structures. Our aim was to develop electronic-equipment specifications that would extract the optimum performance from the PWAS, i.e., maximize the coupling with the structure and obtain large-amplitude Lamb wave transmission and reception. Analytical predictions were compared with measurements made using current laboratory equipment. The comparative analysis revealed that the current electronic equipment does not fully exploit the PWAS capabilities. Hence, the PWAS equipment specifications were divided into two categories: "existing" and "desired". The former category designates integrated electronic equipment that would offer the same PWAS performance as the existing lab equipment, but be of a lower volume/weight/cost. The latter category refers to advanced electronic equipment that will exploit the full potential of PWAS transducers while being of lower volume/weight/cost than the lab equipment. Both categories are presented and discussed in the paper.
Piezoresistive Contactless Position Measurement And Control Using Arduino: An Innovative Approach
2013
A position control mechanism for contactless position measurement has been proposed using servomotor. The servomotor is controlled by a microcontroller based arduino uno board. The motor in turn controls the position of the object whose position is to be detected. The paper proposes an innovative approach to devising a smart sensor. The servo mechanism provides feedback information which in turn helps to improve the accuracy of positioning.