Browsing by Author "Yang, Hanping"

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3D droplet transportations by EWOD actuations on flexible polymer films
(2005)
Yang, Hanping
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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.
Asymmetric electrowetting - moving droplets by a square wave
(2007)
Fan, Shih-Kang
;
Yang, Hanping
;
Wang, Tsu-Te
;
Hsu, Wensyang
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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.
Connecting interface for modularization of digital microfluidics
(2008-01-01)
Yang, Hanping
;
Fan, Shib-Kang
;
Hsu, Wensyang
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機械工程學系
;
奈米科技中心
Here, interconnection technique to link digital microfluidic chips is proposed. Three kinds of digital microfluidic modules with connecting interface, including flexible module and two types of connector modules, are designed and fabricated. Since these modules are fabricated on a compliant polymer-based substrate (ITO PET), chip-to-chip droplet transportation even at different planes can be achieved by the proposed technique. A low-temperature fabrication process is developed for the polymer substrates, where the SU-8 acts as the insulator. Droplet transportation through electrowetting on curved surface is confirmed by testing on the bended flexible modules with different curvatures from 0 to 0.06 mm(-1) at around 70 V-AC. Then the droplet transportations between flexible and connector modules are investigated. It is found that the gap size between two modules and the sidewall profiles at interface affect the droplet transportation directly. For the gap size around 50 mu m with a smooth perpendicular sidewall profile, 80 V-AC is shown to actuate droplet of 1.5 mu l, 2.5 mu l, or 3.5 mu l to cross over the interface successfully.
Connecting interface for modularization of digital microfluidics - art. no. 68860L
(2008)
Yang, Hanping
;
Fan, Shib-Kang
;
Hsu, Wensyang
;
機械工程學系
;
Department of Mechanical Engineering
Here, interconnection technique to link digital microfluidic chips is proposed. Three kinds of digital microfluidic modules with connecting interface, including flexible module and two types of connector modules, are designed and fabricated. Since these modules are fabricated on a compliant polymer-based substrate (ITO PET), chip-to-chip droplet transportation even at different planes can be achieved by the proposed technique. A low-temperature fabrication process is developed for the polymer substrates, where the SU-8 acts as the insulator. Droplet transportation through electrowetting on curved surface is confirmed by testing on the bended flexible modules with different curvatures from 0 to 0.06 mm(-1) at around 70 V-AC. Then the droplet transportations between flexible and connector modules are investigated. It is found that the gap size between two modules and the sidewall profiles at interface affect the droplet transportation directly. For the gap size around 50 mu m with a smooth perpendicular sidewall profile, 80 V-AC is shown to actuate droplet of 1.5 mu l, 2.5 mu l, or 3.5 mu l to cross over the interface successfully.
Droplet-on-a-wristband: Chip-to-chip digital microfluidic interfaces between replaceable and flexible electrowetting modules
(2011)
Fan, Shih-Kang
;
Yang, Hanping
;
Hsu, Wensyang
;
機械工程學系
;
材料科學與工程學系
We present a long (204 mm), curved (curvature of 0.04 mm(-1)), and closed droplet pathway in "droplet-on-a-wristband" (DOW) with the designed digital microfluidic modular interfaces for electric signal and droplet connections based on the study of electrowetting-on-dielectric (EWOD) in inclined and curved devices. Instead of using sealed and leakage-proof pipes to transmit liquid and pumping pressure, the demonstrated modular interface for electrowetting-driven digital microfluidics provides simply electric and fluidic connections between two adjacent parallel-plate modules which are easy-to-attach/detach, showing the advantages of using droplets for microfluidic connections between modules. With the previously reported digital-to-channel interfaces (Abdelgawad et al., Lab Chip, 2009, 9, 1046-1051), the chip-to-chip interface presented here would be further applied to continuous microfluidics. Droplet pumping across a single top plate gap and through a modular interface with two gaps between overlapping plates are investigated. To ensure the droplet transportation in the DOW, we actuate droplets against gravity in an inclined or curved device fabricated on flexible PET substrates prepared by a special razor blade cutter and low temperature processes. Pumping a 2.5 mu l droplet at a speed above 105 mm s(-1) is achieved by sequentially switching the entire 136 driving electrodes (1.5 mm x 1.5 mm) along the four flexible modules of the DOW fabricated by 4-inch wafer facilities.
Integrated Estimation of Vehicle States, Tire Forces, and Tire-Road Friction Coefficients
(2014)
Hsiao, Tesheng
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Lan, Jing-Yuan
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Yang, Hanping
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電機工程學系
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電控工程研究所
Information about the vehicle states (e.g. the sideslip angle and the longitudinal velocity), tire forces, and tire-road friction coefficients is crucial for advanced vehicular active safety systems. In particular, the latest high-performance control system based on optimally distributing and controlling all tire forces requires feedback of the tire forces and the tire-road friction coefficient of each individual tire. Therefore, estimating all or parts of the vehicle/tire/road states from available sensor measurements in production vehicles has long been an active research topic in both academia and industry. Despite recent advances in automotive estimation technologies, it remains an open question on identifying the tire-road friction coefficient of each individual tire. This paper proposes an integrated estimation system that provides accurate estimates of the vehicle/tire/road states from available sensor measurements. More importantly, the tire-road friction coefficient of each tire can be separately estimated. The performance of the proposed estimation system is verified by simulations based on a complex nonlinear vehicle/tire model.