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Sensors and Actuators A: Physical

Sensors and Actuators A: Physical

Archives Papers: 1,817
Elsevier
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Selective bonding method for self-assembly of heterogeneous components using patterned surfaces
Kazuki Kimura; Taiki Okuyama; Taiji Okano; Hiroaki Suzuki;
Abstracts:This study demonstrates the selective bonding of millimeter-scale components using the complementary patterning of hydrophilic and hydrophobic surfaces. The hydrophobic surface of the millimeter-scale components fabricated from hydrophobic polydimethylsiloxane (PDMS) was partially made hydrophilic with a designed pattern by exposure to an excimer light of 172 nm through a stencil mask. We used liquid paraffin as the adhesive and deposited it only on the hydrophobic surface. We prepared twenty components with two different complementary patterns, which were agitated in water by the computer-controlled propeller stirrer. As a result, we succeeded in obtaining a significantly higher yield of correct bonds, in comparison to that of erroneous bonds under an appropriate stirring condition. The result can be explained by the contrast in bonding strength between the correct and erroneous bonds. This principle could be used as a versatile strategy to realize programmed self-assembly with selective bonding patterns.
Contact resonance spectroscopy for on-the-machine manufactory monitoring
Maik Bertke; Michael Fahrbach; Gerry Hamdana; Jiushuai Xu; Hutomo Suryo Wasisto; Erwin Peiner;
Abstracts:A piezo resistive, phase locked loop (PLL) controlled micro tactile measurement system for on-the-machine contact resonance spectroscopy (CRS) mapping of square centimetre-sized areas is developed and characterized. The CRS uses the influence of material parameters like the Young’s modulus on the contact stiffness between probing tip and sample surface and thus, the resonance frequency of the in-contact cantilever. Recently, we showed a robust, large-dimension, piezo resistive silicon cantilever (5 mm × 200 μm × 50 μm) with a silicon tip at its free end for tactile probing of high-aspect-ratio geometries and high-speed topography scans (i.e., up to 15 mm/s). For CRS-based layer and material analysis, this cantilever can be excited into resonance by a piezo chip actuator as described in this work. A compact, LabVIEW-controlled, fully automated scanning system using a homemade, μ-controller-implemented software PLL for resonance frequency tracking and out-reading was realized. To verify the measurement principle, analytical modelling was done. Different layer thicknesses of photo resist (PR) on silicon (11 ± 2 nm to 1653 ± 76 nm), point-by-point line scans of material transitions with various Young’s moduli (Si-PR-Si), bulk materials and nano-/micro-structures were investigated to validate the system. For optimization of the sensor sensitivity and efficiency, amplitude and phase were analysed under different conditions (contact force, excitation amplitudes). On-the-machine CRS with tools and work pieces can be a valuable method for quality assurance and reproducibility of future industrial manufacturing and just-in-time production.
A portable, optical scanning microsystem for large field of view, high resolution imaging of biological specimens
Georgia Korompili; Georgios Kanakaris; Christos Ampatis; Nikos Chronis;
Abstracts:Adapting medical technology for use at the point of care, demands the development of portable, robust and accurate systems for the early diagnosis and monitoring of a wide range of diseases. Microscopy at the point of care, fueled by recent advances in micro-optics, micro-electronics and micro-electromechanical systems, is an emerging and promising field. However, imaging devices already developed remain rather sophisticated and bulky, mainly because of failure to address the most challenging technical limitation: to combine large field-of-view (FOV) with high resolution imaging of biological specimens. To address this need, we developed a portable, optical scanning microsystem that can image - with approximately 1 μm resolution- large areas (6 mm × 40 mm) from various biological samples. This is achieved through the use of a microfabricated - 2D lens array that scans a sample in 1 direction in few minutes. We demonstrated that our system can image blood smear and identify single white blood cells immobilized in a microfluidic chip.
All-dielectric metasurface-based roll-angle sensor
Xiuguo Chen; Ze Tao; Chao Chen; Cai Wang; Li Wang; Hao Jiang; Daniel Fan; Yasin Ekinci; Shiyuan Liu;
Abstracts:We propose and demonstrate an all-dielectric metasurface-based roll-angle sensor, in which the roll angle is translated into the change of polarization state of the probe light. A circular polarization beam splitter is designed and fabricated to split the probe light into right-circularly polarized and left-circularly polarized light beams, whose intensities are then collected to estimate the roll angle. The experimental results show that the developed roll-angle sensor has a measurement resolution of 0.1° and a measurement range of 30°. The all-dielectric metasurface-based design promises to substantially reduce the size of the roll-angle sensor and is expected to gain wide applications especially on space-limited occasions.
High-sensitive ultrasonic sensor using fiber-tip PVC diaphragm Fabry-Perot interferometer and its imaging application
Tingting Gang; Chi Zuo; Xiaobo Liu; Xiaohong Bai; Manli Hu;
Abstracts:A polyvinyl chloride (PVC) diaphragm based on fiber-tip Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic wave (UW) three-dimensional imaging. The sensor probe is created by coating the PVC diaphragm to the end facet of a well-cut single mode fiber (SMF) using a plastic welder. The probe performs with an ultra-high UW sensitivity due to high pressure sensitivity of the PVC, and thus is capable of detecting gradient seismic physical models with different angles. By scanning the model using the proposed sensor in water and three-dimensional signals reconstruction, the imaging of the spherical model is achieved.
A low cost n-SiCN/p-PS/p-Si heterojunction for high temperature ultraviolet detecting applications
Tse-Heng Chou; Ta-Wei Kuo; Chun-Yu Lin; Fu-Shun Lai;
Abstracts:In this paper, we investigated the n-SiCN/p-PS/p-Si heterojunction for low cost and high temperature ultraviolet (UV) detecting applications. The crystalline SiCN film was deposited on p-(100) porous silicon (PS)/silicon substrate with rapid thermal chemical vapor deposition (RTCVD) system. The p-PS serves as a buffer layer with features of high resistivity and flexibility to suppress dark current of an optical sensing device at high temperature. As a result a high photocurrent to dark current ratio (PDCR) can be achieved. At room temperature, the measured PDCR of the n-SiCN/p-PS/p-Si heterojunction with and without irradiation of 254 nm UV light, under −5 V bias and 0.5 mW/cm2 light power is ∼98.3. Even up to 200 °C, the ratio is still high to ∼8.5. These results are better than that of the reported SiCN film or ZnO nanowires on Si substrate UV detectors without the p-PS buffer layer.
Nonlinear-optical switching in gold nanoparticles driven by magneto-optical effects exhibited by carbon nanotubes
J.A. García-Merino; C.L. Martínez-González; M. Trejo-Valdez; H. Martínez-Gutiérrez; C. Torres-Torres;
Abstracts:Herein is addresses the application of attractive and large magnetization of carbon nanotubes for modulating optical signals. A cascade system based on multiwall carbon nanotubes in thin film form and Au nanoparticles embedded in a TiO2 thin solid film were combined to achieve a nonlinear magneto-optical switching action. An all-optical switching device rising from an optical Kerr effect in the second stage is proposed to transmit a magneto-optical signal from the first stage. Multiwall carbon nanotubes with large magnetic sensitivity were incorporated in the arm of a Michelson interferometer to promote a change in the refractive index due to the Aharonov-Bohm effect. The Michelson interferometer was monitoring magneto-optical processes by a 532 nm wavelength. The second stage was recorded with a 532 nm nanosecond two-wave mixing configuration testing Au nanoparticles embedded in a TiO2 thin film. The development of simultaneous all-optical and magneto-optical systems is attractive since multifunctional quantum operations can be contemplated to be performed in low-dimensional platforms. In this paper is proposed a switching device that exploits interferometry for detecting magnetic signals and optical Kerr gating with the advantages of distinct nanostructures.
A flexible sensing system capable of sensations imitation and motion monitoring with reliable encapsulation
Menglu Li; Lei Zheng; Tianbai Xu; Hualei Wo; Umar Farooq; Weiqiang Tan; Changqian Bao; Xiaozhi Wang; Shurong Dong; Wei Guo; Jikui Luo; Jong Min Kim;
Abstracts:In this work, a flexible multiple sensor system is demonstrated for robotic and prosthetic applications. The system consists of two strain sensors, a microheater, a temperature sensor and a pressure sensor for imitating different sensations of human skin. The strain sensors are designed for monitoring the movement and bending angle of the fingers; while the temperature and pressure sensors are used to collect the information of temperature, grabbing force and stiffness of the objects being grabbed, respectively. Combination of the temperature sensor and microheater mimics the temperature sensation of human skin, allowing measuring temperature and apparent temperature of the objects grasped. Liquid metal with reliable polymer encapsulation is innovatively used to interface the sensor system with peripheral circuits. This allows reliable signal transmission and processing for the flexible sensor system for strains up to 40%. This multiple sensor system is capable of precisely monitoring movement of fingers, providing different sensations and judging some characteristics of objects for a robot hand.
Efficient electrode configuration for electro-conjugate fluid flow generation with dibutyl decanedioate: Experimental and theoretical investigation
Y. Kuroboshi; K. Takemura; K. Edamura;
Abstracts:Electro-conjugate fluid (ECF) is a functional fluid that can generate a high-power flow induced by a high direct-current voltage. While ECF has been used in various fields, including mechanical, chemical, and biomedical systems, its underlying principles have not been sufficiently understood to be applicable to ECF system design, and the lack of theoretical models hampers further applications of ECF. This study aims to investigate underlying principles of ECF flow generation with a rectangular-slit electrode pair. By analyzing the effect of electrode configuration on the flow generation, this paper proposes a theoretical model for electrode design for efficient flow generation. The proposed model has been validated by comparing the simulation results with the visualized characteristics from flow experiments. The results show that the flow rate can be controlled by changing the electrode configuration with the maximum flow rate with the rectangular-slit electrode gap of 1.0 mm and the slit electrode gap of 5.0 mm.
Three dimensional force estimation for steerable catheters through bi-point tracking
Junghwan Back; Lukas Lindenroth; Kawal Rhode; Hongbin Liu;
Abstracts:Contact forces play a significant role in the success of cardiac ablation. However, it is still challenging to estimate the applied contact force during the intervention when a catheter is under large bending or experiences multiple contact points along its body. A multi-element kinetostatic model of a tendon-driven catheter is proposed for real-time intrinsic force sensing. The model is able to accurately predict the steerable section shape of the catheter for given tendon tensions as well as the contact force at any known location on the steerable section. An algorithm is proposed which estimates the contact force on the steerable section using the model-based shape prediction in combination with end-position tracking of the steerable section. In this paper, undefined parameters and contact states of the force and shape estimation are defined and investigated. The shape prediction is validated in 3D space. The contact force estimation is validated with different catheter shpae, contraint catheter and buckling. It can be seen that end-position of the steerable section can be predicted with an accuracy of about 2.3 mm. In the validations, the 3-dimensional contact forces can be estimated accurately with an error of about 0.018 N and 1.6 ms computation time. Furthermore, the contact force estimation algorithm are able to incorporate external physical constraints along the catheter, which is validated in an experimental setup.
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