Browsing by Author "Wu, Cheng-Hua"

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A fluorene-modified porphyrin for efficient dye-sensitized solar cells
(2012)
Wu, Cheng-Hua
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Pan, Tsung-Yu
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Hong, Shang-Hao
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Wang, Chin-Li
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Kuo, Hshin-Hui
Porphyrins bearing a polyaromatic or a heterocyclic group are prepared to study their fundamental and photovoltaic properties. Solar cells sensitized with a fluorene-modified porphyrin outperform other dyes in the series, reaching similar to 90% efficiency of N719 dye.
Balance Control and Energetics of Powered Exoskeleton-Assisted Sit-to-Stand Movement in Individuals With Paraplegic Spinal Cord Injury
(2018-10-01)
Mao, Hui-Fen
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Huang, Hsing-Po
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Lu, Tung-Wu
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Wang, Ting-Ming
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Wu, Cheng-Hua
Objective: To quantify the effects of initial hip angle and angular hip velocity settings of a lower-limb wearable robotic exoskeleton (WRE) on the balance control and mechanical energy requirements in patients with paraplegic spinal cord injuries (SCIs) during WRE-assisted sit-to-stand (STS). Design: Observational, cross-sectional study. Setting: A university hospital gait laboratory with an 8-camera motion analysis system, 3 forceplates, a pair of instrumented crutches, and a WRE. Participants: Patients (N = 12) with paraplegic SCI. Interventions: Not applicable. Main Outcome Measures: The inclination angle (IA) of the body's center of mass (COM) relative to the center of pressure (COP), and the rate of change of IA (RCIA) for balance control, and the mechanical energy and forward COM momentum before and after seat-off for energetics during WRE-assisted STS were compared between conditions with 2 initial hip angles (105 degrees and 115 degrees) and 3 initial hip angular velocities (800, 1000, 1200 rpm). Results: No interactions between the main factors (ie, initial hip angle vs angular velocity) were found for any of the calculated variables. Greater initial hip angle helped the patients with SCI move the body forward with increased COM momentum but reduced RCIA (P<.05). With increasing initial angular hip velocity, the IA and RCIA after seat-off (P<.05) increased linearly while total mechanical energy reduced linearly (P<.05). Conclusions: The current results suggest that a greater initial hip angle with smaller initial angular velocity may provide a favorable compromise between momentum transfer and balance of the body for people with SCI during WRE-assisted STS. The current data will be helpful for improving the design and clinical use of the WRE. (C) 2018 by the American Congress of Rehabilitation Medicine
Highly efficient porphyrin-sensitized solar cells with enhanced light harvesting ability beyond 800 nm and efficiency exceeding 10%
(2014-04-01)
Wang, Chin-Li
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Hu, Jyun-Yu
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Wu, Cheng-Hua
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Kuo, Hshin-Hui
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Chang, Yu-Cheng
A new porphyrin sensitizer, LD31, was designed based on a donorp- pi-acceptor structure, in which an ethynyl-anthracenyl moiety was inserted between the dioctylaminophenyl group and the porphyrin core in order to extend the p-conjugation of the dye for improved light-harvesting ability. The device made of LD31 exhibited panchromatic spectral features covering the whole visible region and further extending over 800 nm. When combined with an organic dye (AN-4), the performance of the LD31/AN-4 co-sensitized device attained JSC/ mA cm(-2) = 20.3, VOC/mV = 704, FF = 0.72, and the overall efficiency of power conversion eta=10.3%.
Study on the characteristics of a homemade differential-velocity-type compliant joint for robotic manipulators
(2015-09-01)
Hu, Jwu-Sheng
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Wu, Cheng-Hua
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Tsai, Yi-Jeng
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Kuo, Chung-Hsien
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電子工程學系及電子研究所
Design of a new differential-velocity-type compliant joint with two motors is proposed for robotic manipulators. The speed/output torque of the differential-velocity-type joint is synthesized by controlling the differential speeds of a pair of actuators. Descriptions of the design concept, theoretical analysis, and the experiments are presented in this article. The experimental results showed that (1) the stiffness of the differential-velocity-type joint can be regulated by changing the speeds of both motors, (2) the differential-velocity-type joint actually reduced 7.9%-15.7% time compared with the single-drive joint when performing five cycles of reciprocation, and (3) a new design of delta-type robot with differential-velocity-type driving modules was developed for verification. The experimental results showed that the differential-velocity-type delta robot can perform flexible assembly operations within a 0.028-mm tolerance.
The effects of gait training using powered lower limb exoskeleton robot on individuals with complete spinal cord injury
(2018-03-05)
Wu, Cheng-Hua
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Mao, Hui-Fen
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Hu, Jwu-Sheng
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Wang, Ting-Yun
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Tsai, Yi-Jeng
Background: Powered exoskeleton can improve the mobility for people with movement deficits by providing mechanical support and facilitate the gait training. This pilot study evaluated the effect of gait training using a newly developed powered lower limb exoskeleton robot for individuals with complete spinal cord injury (SCI). Methods: Two participants with a complete SCI were recruited for this clinical study. The powered exoskeleton gait training was 8 weeks, 1 h per session, and 2 sessions per week. The evaluation was performed before and after the training for (1) the time taken by the user to don and doff the powered exoskeleton independently, (2) the level of exertion perceived by participants while using the powered exoskeleton, and (3) the mobility performance included the timed up-and-go test, 10-m walk test, and 6-min walk test with the powered exoskeleton. The safety of the powered exoskeleton was evaluated on the basis of injury reports and the incidence of falls or imbalance while using the device. Results: The results indicated that the participants were donning and doffing the powered lower limb exoskeleton robot independently with a lower level of exertion and walked faster and farther without any injury or fall incidence when using the powered exoskeleton than when using a knee-ankle-foot orthosis. Bone mineral densities was also increased after the gait training. No adverse effects, such as skin abrasions, or discomfort were reported while using the powered exoskeleton. Conclusions: The findings demonstrated that individuals with complete SCI used the powered lower limb exoskeleton robot independently without any assistance after 8 weeks of powered exoskeleton gait training.