Browsing by Author "Hsu, Wensyang"

Now showing 1 - 20 of 65

3D droplet transportations by EWOD actuations on flexible polymer films
(2005)
Yang, Hanping
;
Fan, Shih-Kang
;
Lin, Chang-Pau
;
Wu, Chien-Tai
;
Hsu, Wensyang
3-D droplet transportation of ElectroWetting On Dielectric (EWOD) actuation with flexible substrate is proposed. Instead of glass substrate, a polymer film is taken to fabricate the microfluidic device for the droplet demonstrating out of plane motions. Two kinds of tests, tilted test and curved test, are performed, and a model of minimum required actuation voltage is presented, and compared with the results of tilted test. The current model matches experiment data much better than the conventional ones. In the curved test, the droplet successfully transports from bottom to the top.
3D PRINTED RF PASSIVE COMPONENTS BY LIQUID METAL FILLING
(2015)
Yang, Chen
;
Wu, Sung-Yueh
;
Glick, Casey
;
Choi, Yun Seok
;
Hsu, Wensyang
We present three-dimensional (3D) micro-scale electrical components and systems by means of 3D printing and a liquid-metal-filling technique. The 3D supporting polymer structures with hollow channels and cavities are fabricated from inkjet printing. Liquid metals made of silver particles suspension in this demonstration are then injected into the hollow paths and solidified to form metallic elements and interconnects with high electrical conductivity. In the proof-of-concept demonstrations, various radio-frequency (RF) passive components, including 3D-shaped inductors, capacitors and resistors are fabricated and characterized. High-Q inductors and capacitors up to 1 GHz have been demonstrated. This work establishes an innovative way to construct arbitrary 3D electrical systems with efficient and labor-saving processes.
3D-printed microelectronics for integrated circuitry and passive wireless sensors
(2015-01-01)
Wu, Sung-Yueh
;
Yang, Chen
;
Hsu, Wensyang
;
Lin, Liwei
;
機械工程學系
Three-dimensional (3D) additive manufacturing techniques have been utilized to make 3D electrical components, such as resistors, capacitors, and inductors, as well as circuits and passive wireless sensors. Using the fused deposition modeling technology and a multiple-nozzle system with a printing resolution of 30 mu m, 3D structures with both supporting and sacrificial structures are constructed. After removing the sacrificial materials, suspensions with silver particles are injected subsequently solidified to form metallic elements/interconnects. The prototype results show good characteristics of fabricated 3D microelectronics components, including an inductor-capacitor-resonant tank circuitry with a resonance frequency at 0.53 GHz. A 3D "smart cap" with an embedded inductor-capacitor tank as the wireless passive sensor was demonstrated to monitor the quality of liquid food (e.g., milk and juice) wirelessly. The result shows a 4.3% resonance frequency shift from milk stored in the room temperature environment for 36 h. This work establishes an innovative approach to construct arbitrary 3D systems with embedded electrical structures as integrated circuitry for various applications, including the demonstrated passive wireless sensors.
A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay
(2016-01)
Huang, Cheng-Yeh
;
Tsai, Po-Yen
;
Lee, I-Chin
;
Hsu, Hsin-Yun
;
Huang, Hong-Yuan
Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications. (C) 2016 AIP Publishing LLC.
A novel fabrication method of microlens array by surface tension and injection process
(2007)
Lin, Yu-Hsin
;
Hsu, Wensyang
;
機械工程學系
;
Department of Mechanical Engineering
A novel and simple method on. fabricating Ultra-Violet curable polymer microlens array on silicon membrane and cantilever by injection process is presented. The radius of curvature of microlens can be tuned by liquid polymer surface tension and applied pressure. The polymer microlens array, with a diameter of 17 mu m, a pitch of 30 mu m on silicon membrane and cantilever are successfully fabricated to demonstrate the feasibility of the proposed method. Also, it is shown that different curvature radius of microlens can be fabricated, and the proposed method has potential to integrate with other optical device.
A Novel Guiding Device for Distal Locking of Intramedullary Nails
(2012)
Lee, Meng-Shiue
;
Wu, Sung-Yueh
;
Wong, Tze-Hong
;
Hsu, Wensyang
;
Chung, Tien-Kan
This paper presents the prototype of a new remote guiding device to find the accurate screw hole position for drilling and direction for locking in intramedullary nailing surgery. The device consists of three magnetic pins and an electrical conductive board. The three symmetrically placed magnetic pins can rotate freely and point to the permanent magnet inside the nail. The drilling position and screwing direction can be obtained by moving the device with those magnetic pins to align with the magnet in the nail. The alignment condition is indicated by a LED. When the device is not aligned with the magnet in the nail properly, either in position or direction, the pins then will contact with the board to trigger a light-emitting diode for alarming.
A novel self-aligned process between a nano-aperture and a solid immersion lens for a near-field optical system
(2006-12-01)
Hsu, Hung-Lung
;
Chang, Yu-Ru
;
Chiu, Yi
;
Lin, Yu-Hsin
;
Hsu, Wensyang
For near-field optical systems, an aperture in nano-size and a solid immersion lens (SIL) are two popular methods to overcome the diffraction limit and reduce the optical spot size. In previous research, combining a nano-aperture and SIL has been proposed to provide high throughput and ultra-high resolution. However, alignment between the nano-aperture and SIL is very critical in the fabrication process, and no effective alignment technique has been investigated yet. In this research, a novel self-alignment technique is proposed for the combination of the nano-aperture and SIL, where the nano-aperture is fabricated with the focused ion beam (FIB) system and the SIL is formed by the thermal reflowing process. The self-alignment technique is based on the backside exposure and the surface tension self-modulation technique during the thermal reflowing process. The maximum deviation of the fabricated SIL is less than 3% in comparison with the designed values. A SIL of 15 mu m diameter has been measured with 65.2% transmission efficiency. The polymer SIL combined with the circular aperture of 329 nm diameter has 1.68 times enhancement on throughput compared with the circular aperture of 329 nm alone. This result shows that the SIL can effectively enhance the throughput of the nano-aperture, and the feasibility of the proposed self-alignment method is also verified.
A Novel Suspension Design for MEMS Sensing Device to Eliminate Planar Spring Constants Mismatch
(2012)
Jiang, Kai-Yu
;
Chen, He-Ling
;
Hsu, Wensyang
;
Lee, Yueh-Kang
;
Miao, Yen-Wu
This paper presents a new suspension design for planar MEMS sensing devices. The new design includes four coil springs which are symmetrically arranged with respect to the center of the proof mass with 90-degree orientation difference. The proposed coil spring design is found to take less area to achieve similar spring constant than the conventional serpentine spring design. Furthermore, the proposed symmetrical-to-center arrangement on suspension can reduce spring constants mismatch between X and Y axes, even under beam width deviation due to fabrication resolution. This concept is realized and verified by experimental results from two-axis capacitive accelerometers through a polysilicon-based CMOS fabrication platform.
A Rapid Fatigue Test Method on Micro Structures for High-Cycle Fatigue
(2016-03)
Shieh, Yi-Chueh
;
Lin, Hsuan-Yu
;
Hsu, Wensyang
;
Lin, Yu-Hsin
;
機械工程學系
Here, a rapid fatigue test method for micro structure is proposed, where the test sample is excited at its resonant frequency by an external actuator. Due to the scaling effect, a micro cantilever beam has high resonant frequency, so the testing time can be greatly reduced. In addition, no complicated built-in micro actuator is needed; therefore, it is easy to fabricate the test sample. Single-crystal silicon (SCS) beams are fabricated to demonstrate the proposed method here with two types of beams. A notch is designed near the fixed end to have stress concentration effect. The input voltage of the piezoelectric patch is adjusted to excite the cantilever beams at its resonant frequency to have different amplitudes to find the corresponding fatigue life, where a laser Doppler vibrometer is used to monitor displacements of the cantilever beam to control the stress amplitude. Then, the stress-life (S/N) curve of the silicon beam can be obtained. It is found that the fatigue limit of the SCS beam is about 1.33 GPa, and it takes only about 5.2 h to test 1.35 x 10(9) cycles at a resonant frequency of 72 kHz. Comparing with previous fatigue test methods with an external probe, testing 10(9) cycles at a frequency of 20 Hz will need 1.58 years, which indicates that the proposed rapid fatigue test method is particularly suitable for high-cycle fatigue test of micro structure.
A Resettable, Wireless and Passive Fall-Down Recorder Using a Magnetic Droplet With an LC Circuit
(2016-02-01)
Huang, Cheng-Yeh
;
Sun, Peng
;
Lee, Meng-Shiue
;
Wu, Sung-Yueh
;
Shieh, Yi-Chueh
A fall-down recorder can record the happening of an object falling down during object delivery or transportation, even after the object is recovered to its initial state. Here, a resettable, wireless and passive fall-down recorder is proposed by integrating a droplet-based inertial force switch with the inductor-capacitor (LC) circuit for wireless signal transmission. A magnetic droplet is used in the switch with a converging microchannel to control the desired threshold acceleration. When the inertial force exceeds the designed threshold acceleration, the magnetic droplet will pass through the converging microchannel to a deep cavity to become a different state. By connecting the switch with the sensing LC circuit, the state of the recorder can be wirelessly identified through the LC resonant frequency. After triggering, this switch can be remotely reset to its initial state by an external magnet. A proper hydrophobic surface treatment is employed to facilitate the movement of the magnetic droplet and reduce the variation on the threshold acceleration. The capabilities, including switching, recording, wireless reading, and resetting of the proposed fall-down recorder, are successfully designed, fabricated, and verified with ten recording-reset tests.
A Reversible Micro Mechanical-latch Shock Switch by External Magnetic Field
(2012)
Shieh, Yi-Chueh
;
Ma, Ruei-Pin
;
Hsu, Wensyang
;
Lin, Yu-Hsin
;
Tang, Yu-Hsiang
A reversible passive micro mechanical-latch shock switch made of nickel is designed, fabricated, and tested here. Unlike previous reversible mechanical-latch shock switches, which need built-in micro actuators to unlock the latch, the design proposed here utilizes external magnetic field to unlock the switch after experiencing impact over threshold level. Therefore, the switch is reusable and compact due to no built-in micro actuator.
A simulation model on photoresist SU-8 thickness after development under partial exposure with reflection effect
(2014-03-01)
Huang, Yuan-Te
;
Hsu, Wensyang
;
機械工程學系
;
Department of Mechanical Engineering
The negative photoresist SU-8 is often used to fabricate thick micro structures. It was known that reflection from the interface between SU-8 and the substrate surface would affect the thickness after development and profile of SU-8 structures. However, the model to predict the thickness after development of SU-8 under reflection effect has not been reported yet. Here, a simulation model to predict SU-8 thickness after development under partial exposure with reflection effects is proposed. Two kinds of SU-8 micro structures with different exposure dosages and coated thickness are fabricated on glass substrates to demonstrate the Capability of the proposed model. For different exposure dosages or coated SU-8 thickness, the maximum difference between simulated and experimental results is shown to be less than 3.1%, which verifies the accuracy of the proposed model. (C) 2014 The Japan Society of Applied Physics
A wafer-level hermetic encapsulation for MEMS manufacture application
(2006-08-01)
Liang, Zhi-Hao
;
Cheng, Yu-Ting
;
Hsu, Wensyang
;
Lee, Yuh-Wen
;
機械工程學系
In order to simplify the processing complexity and cut down the manufacturing cost, a new wafer bonding technique using ultraviolet (UV) curable adhesive is introduced here for microelectromechanical systems (MEMS) device packaging and manufacturing applications. UV curable adhesive is cured through UV light exposure without any heating process that is suitable for the packaging of temperature-sensitive materials or devices. A Pyrex 7740 glass is chemically wet etched to form microcavities and utilized as the protection cap substrate. After a UV-curable adhesive is spin-coated onto the glass substrate, the substrate is then aligned and bonded through UV light exposure with a device substrate below. Electrical contact pad opening and die separation are done simultaneously by dicing. Two different testing devices, a dew point sensor and capacitive accelerometer, are built to evaluate the package strength and hermeticity. After the dicing process, no structural damage or stiction phenomenon is found in the packaged parallel capacitor. The acceleration test results also indicate that the package using the Loctite 3491 UV adhesive with 150 mu m bond width can survive more than 300 days at a 25 degrees C and 100% relative humidity working environment.
A wirelessly readable and resettable shock recorder through the integration of LC circuits and MEMS devices
(2014-09-01)
Wu, Sung-Yueh
;
Hung, Chen-Yuan
;
Hsu, Wensyang
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a passive shock recorder to record shock events for tens of Gs with wireless reading and wireless resetting capabilities through the integration of LC circuits and two MEMS devices. With a micro mechanical-latch shock switch electrically connected to the sensing LC circuit, the shock event that leads to different latching states can be recorded and wirelessly read through the LC resonant frequency. With a micro electro-thermal actuator electrically connected to a wirelessly powered actuating LC circuit, the energy can be wirelessly sent to the micro actuator to provide the necessary unlatched force. By integrating the mechanical-latch shock switch and actuator with LC circuits, the latching state can be reset through the wireless actuation. Therefore, the shock recorder can be used repeatedly. Here, the mechanical-latch shock switch is designed to have a two-level shock recording capability. The fabrication of the shock switch and actuator are achieved by a Ni-based surface micromachining process. When the acceleration reaches 28.06 G, the latching state changes from the original state to the first latching state. The resonant frequency of sensing for the LC circuit is found to switch from 10.14 MHz to 9.16 MHz, correspondingly. By further applying acceleration up to 37.10 G, the latching state changes from the first latching state to the second state, and the resonant frequency shifts to 7.83 MHz. Then, with a current of 2.07 A(AC) wirelessly induced in the actuating LC circuit, the micro electro-thermal actuator is shown to provide sufficient displacement to reset the shock switch from a latched state back to the original unlatched state, and the resonant frequency is switched back to 10.14 MHz. The fabricated shock recorder is repeatedly tested five times. The wireless reading, resetting and shock recording capabilities are successfully verified.
AMPFLUID: Aggregation Magnified Post-Assay Fluorescence for Ultrasensitive Immunodetection on Digital Microfluidics
(2015-02-01)
Huang, Cheng-Yeh
;
Shih, Po-Huai
;
Tsai, Po-Yen
;
Lee, I-Chin
;
Hsu, Hsin-Yun
Several strategies are currently employed to enhance the detection limit of bead-based assays, but all these approaches improve the sensitivity by varying the assay procedures chemically or biologically. In previous digital microfluidic setups for bead-based immunoassay, the magnetic beads were suspended for detection. We investigated the effect of bead aggregation in such an immunoassay system and propose the aggregation magnified post-assay fluorescence for ultrasensitive immunodetection on digital microfluidics (AMPFLUID). The detection signal and sensitivity are further enhanced even at the post-assay stage without altering the original assay protocol on employing magnetically triggered post-assay aggregation of beads in a digital microfluidic setup followed by processing of the fluorescent signal. This method is shown to enhance the fluorescent signal with increased consistency and sensitivity after appropriate charge-coupled device (CCD) calibration. This method of on-chip detection allows the fulfilment of consumption of a volume at the nanoliter level and a limit of detection in the range picogram/mL. In our sTNF-RI model immunoassay, only 2.5 nL of sample is required; a detection limit 15 pg/mL is achieved. The decreased uncertainty of the measure is indicated by the error bars and coefficient of variation.
An analytical model for calculating the pull-in voltage of micro cantilever beams subjected to tilted and curled effects
(2014-08-01)
Huang, Yuan-Te
;
Chen, He-Ling
;
Hsu, Wensyang
;
機械工程學系
;
Department of Mechanical Engineering
Pull-in is a fundamental phenomenon in electrostatic micro devices. In previous studies on modeling the pull-in voltage of suspended micro cantilever beam subject to residual stress, only curled deformation was considered. This study proposed a modified deformation function, which considered both curled and tilted deformations caused by gradient stress and mean stress, to calculate the pull-in voltage of the suspended cantilever beam with residual deformations. In order to verify the proposed analytical model, suspended poly-silicon cantilever beams with three different lengths, 260 mu m, 295 mu m and 330 mu m, are fabricated through surface micromachining process. It is shown that the residual deformations include both curled and tilted deformations, where the tilted angle and radius of curvature can be identified by white light interferometer (WLI). By comparing the analytical results with measurement results on pull-in voltages, it is found that while only considering curled effect, the average error of calculated pull-in voltage is 10.5%. On the other hand, when both tilted and curled effects are considered, the average error is reduced to 3.2%, which verifies the accuracy improvement of the proposed analytical model. (C) 2014 Elsevier B.V. All rights reserved.
An Electromagnetic-Induction Approach for Screw-Hole Targeting in Interlocking-Nail Surgery
(2012)
Chung, Tien-Kan
;
Chu, Hou-Jen
;
Wong, Tze-Hong
;
Hsu, Wensyang
;
Lee, Meng-Shiue
We report a novel approach for targeting screw-holes of an intramedullary nail in a long-bone fracture surgery. The approach utilizes the electromagnetic induction to avoid over exposure of radioactivity which is the critical issue in conventional X-ray-imaging targeting method. Based on the approach, we fabricate a targeting system. The targeting system consists of a c-shaped electromagnet, detecting-coil, guiding-mechanism, and measurement electronics. When a voltage is applied to the electromagnet, magnetic flux is generated in the air gap of the electromagnet and subsequently detected by the coil. When the flux is detected by the coil, a voltage response is induced in the coil. When a nail in a bone is scanned through the air gap of the electromagnet, the flux is influenced due to a discrepancy of the permeability between the location with and without the hole of the nail. The influenced flux induces different voltage response in the coil. Through analyzing the voltage response, we establish a criterion for targeting the holes. By the criterion, the experimental result shows the maximum error of targeting a hole with a diameter of 5 mm is less than 2.5 mm.
An EWOD-based micro diluter with high flexibility on dilution ratio
(2017-08-01)
Wang, Ying-Bin
;
Huang, Jun-Hao
;
Lee, Meng-Shiue
;
Huang, Cheng-Yeh
;
Huang, Cheng-Sheng
Dilution is a common procedure in biological and chemical analyses to perform tests at different concentrations. In previously reported micro diluters, although they could provide a wide dilution range, only limited dilution ratios were demonstrated, i.e. low flexibility in dilution ratio. Here, a droplet-based micro diluter with high flexibility on dilution ratio is proposed, fabricated, and tested. Through combination of five different electrode sizes using electrowetting-on-dielectric (EWOD) technique, the proposed micro diluter can provide 49 dilution ratios at dilution range from 1/2 to 1/50. Experimental results verify that different dilution ratios can be successfully generated, even at the most difficult low concentration range. Comparing to the design with equal electrode size in conventional EWOD-based microfluidic chip, the proposed design with unequal electrode sizes can reduce the operation steps to achieve high flexibility on dilution ratios efficiently.
An Implantable Drug-delivery System on a Chip
(2015-01-01)
Lee, Meng-Shiue
;
Yao, Da-Jeng
;
Hsu, Wensyang
;
機械工程學系
;
Department of Mechanical Engineering
An implantable system for drug delivery provides a new strategy for drug therapy, and typically involves a microfluidic chip produced with micro or nano-technology. Implantable systems have the flexibility to conform various schemes of drug release, including zero order, pulsatile, and on demand dosing, as opposed to a standard sustained release profile. Such an implantable system is classified as allowing either controllable or uncontrollable drug release after implantation, so an active or passive delivery system respectively. The performance and related applications of these systems vary. The key points of each technology are highlighted such as performance, working principle, fabrication methods, and dimensional constrains. We here review the implantable drug-delivery system in current research with a focus on application and chip performance, and comparison for passive and active delivery system.
Asymmetric electrowetting - moving droplets by a square wave
(2007)
Fan, Shih-Kang
;
Yang, Hanping
;
Wang, Tsu-Te
;
Hsu, Wensyang
;
機械工程學系
Here droplet oscillation and continuous pumping are demonstrated by asymmetric electrowetting on an open surface with embedded electrodes powered by a square wave electrical signal without control circuits. The polarity effect of electrowetting on an SU-8 and Teflon coated electrode is investigated, and it is found that the theta-V ( contact angle-applied voltage) curve is asymmetric along the V = 0 axis by sessile drop and coplanar electrode experiments. A systematic deviation of measured contact angles from the theoretical ones is observed when the electrode beneath the droplet is negatively biased. In the sessile drop experiment, up to a 10 degrees increment of contact angle is measured on a negatively biased electrode. In addition, a coplanar electrode experiment is designed to examine the contact angles at the same applied potential but opposite polarities on two sides of one droplet at the same time. The design of the coplanar electrodes is then expanded to oscillate and transport droplets on square-wave-powered symmetric ( square) and asymmetric ( polygon) electrodes to demonstrate manipulation capability on an open surface. The frequency of oscillation and the speed of transportation are determined by the frequency of the applied square wave and the pitch of the electrodes. Droplets with different volumes are tested by square waves of varied frequencies and amplitudes. The 1.0 mu l droplet is successfully transported on a device with a loop of 24 electrodes continuously at a speed up to 23.6 mm s(-1) when a 9 Hz square wave is applied.