Browsing by Author "Wang, Yen-Chieh"

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Flexible Linear and Angular Displacement Sensor Based on a Gradient Guided- Mode Resonance Filter
(2018-12-15)
Wang, Yen-Chieh
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Huang, Cheng-Sheng
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機械工程學系
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Department of Mechanical Engineering
This paper reports a method for micrometer-scale linear and angular displacement measurement based on a gradient grating period guided-mode resonance (GGP-GMR) filter. When the filter is mounted on a moving or rotating object, the displacement on the object can be observed through the changes in the resonant wavelength, which are detected by the GGP-GMR filter. In this paper, the GGP-GMR filter comprised grating periods from 250 to 550 nm with 2-nm increments. Each period comprised 100 repeated cycles, resulting in a total length of 6 mm. For linear displacement, we achieved an average sensitivity of 67 nm/mm for a detection range of 6 mm and a theoretical limit of detection of 3 mu m. To demonstrate the measurement of angular displacement, the GGP-GMR filter was attached to a cylinder with a diameter of 8 cm. The experimental results revealed an average sensitivity of 51.7 nm/degrees for a range of 7 degrees and an experimental limit of detection of 0.002 degrees.
Lightweight Torque Sensor Based on a Gradient Grating Period Guided-Mode Resonance Filter
(2019-08-15)
Wang, Yen-Chieh
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Jang, Wen-Yea
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Huang, Cheng-Sheno
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機械工程學系
;
Department of Mechanical Engineering
This paper describes the design, fabrication, and testing of a lightweight and compact torque sensor system based on a gradient grating period guided-mode resonance (GGP-GMR) filter and a flexure-elastic-force-sensing element. The GMR filter exhibits a characteristic resonant reflection, when illuminated with a broadband light source at normal incidence. Instead of a fixed grating period, the GGP-GMR filter consists of grating periods varying from 250 to 550 nm with an increment of 2 nm. Given the flexibility of the plastic-based GGP-GMR filter, it can be bent conform to the cylindrical surface of the flexure. The applied torque induced deformation of the flexure and angular displacement of the attached GGP-GMR. For a stationary light source, the angular displacement of the GGP-GMR filter results in illumination at different locations (grating periods), leading to a shift of the resonant reflection wavelength. The magnitude of shift in the reflection wavelength can be correlated to the magnitude of deformation and the applied torque. In addition, commercial software based on the finite element method was used to simulate the proposed design, which indicates that the flexure made of medium-carbon steel can withstand the torque of 35 Nm without yielding. Furthermore, the simulation results (torque-induced deformation) were consistent with those obtained using the proposed torque sensor system. Torque measurements from 0 to 25 Nm showed good linearity. The limit of detection achieved was 0.77 Nm.
Resonant wavelength shift detection system based on a gradient grating period guided-mode resonance filter
(2018-01-01)
Chang, Chih-Wei
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Chen, Shi-Ting
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Wang, Yen-Chieh
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Huang, Cheng-Sheng
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機械工程學系
A resonant wavelength detection system based on a gradient grating period guided-mode resonance (GGP-GMR) filter and a linear charge-coupled device is demonstrated. The GGP-GMR used in this work consists of a subwavelength grating structure with a grating period varying from 250-550 nm in increments of 2 nm. We successfully demonstrate that by using this system, we can monitor the shift in a biosensor's dip wavelength caused by different sucrose concentrations. This technology has the potential to replace a bulky and expensive spectrometer used in most optical biosensor systems. Given its compactness, the system can be integrated with lab-on-a-chip systems for numerous biosensing applications.