Browsing by Author "Chang, Jui-Wen"

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A novel nanostructured supramolecular hydrogel self-assembled from tetraphenylethylene-capped dipeptides
(2016)
Yeh, Mei-Yu
;
Huang, Chen-Wei
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Chang, Jui-Wen
;
Huang, Yu-Tang
;
Lin, Jhong-Hua
Herein, we report a tetraphenylethylene-diglycine (TPE-GG) hydrogelator from a systematic study of TPE-capped dipeptides with various amphiphilic properties. From a chemical design, we found that the hydrogelation of TPE-GG molecules can be utilized to generate supramolecular nanostructures with a large TPE-based nanobelt width (similar to 300 nm) and lateral dimension ratio (>30 fold). In addition, TPE-GG has the lowest molecular weight and minimum number of atoms compared to any TPE-capped peptide hydrogelator reported to date. This minimal self-assembled hydrogelator can fundamentally achieve the gel features compared with other TPE-capped peptides. A combined experimental and computational study indicates the pi-pi interactions, electrostatic interactions and hydrogen-bonding interactions are the major driving forces behind the formation of self-assembled nanobelts. This study demonstrates the importance of structure-property relationships and provides new insights into the design of supramolecular nanomaterials.
A supramolecular hydrogel self-assembled from pentafluorobenzyl-dipeptide
(2015-01-01)
Hsu, Shu-Min
;
Chang, Jui-Wen
;
Wu, Fang-Yi
;
Lin, Yu-Chun
;
Lai, Tsung-Sheng
We report a new aromatic-capped peptide amphiphile which is able to form a supramolecular hydrogel under neutral pH. This hydrogel can also be obtained by enzymatic transformation from the hydrogelator precursor. The newly discovered hydrogel has excellent biocompatibility for four different cell lines, thus making it a potentially useful scaffolding material for biomedical applications.
An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring
(2016-03-01)
Chung, Tien-Kan
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Yeh, Po-Chen
;
Lee, Hao
;
Lin, Cheng-Mao
;
Tseng, Chia-Yung
An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.
Intramolecular Interactions of a Phenyl/Perfluorophenyl Pair in the Formation of Supramolecular Nanofibers and Hydrogels
(2014-02-10)
Hsu, Shu-Min
;
Lin, Yu-Chun
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Chang, Jui-Wen
;
Liu, Yu-Hao
;
Lin, Hsin-Chieh
A new system for the incorporation of a phenyl/perfluorophenyl pair in the structure of a peptide hydrogelator was developed. The strategy is based on the idea that the integration of an end-capped perfluorophenyl group and a phenylalanine with a phenyl moiety in the side chain forms an intramolecular phenyl/perfluorophenyl pair, which can be used to promote the formation of the supramolecular nanofibers and hydrogels. This work illustrates the importance of structure-hydrogelation relationship and provides new insights into the design of self-assembly nanobiomaterials.
Self-Powered Wireless Vibration-Sensing System for Machining Monitoring
(2013)
Chung, Tien-Kan
;
Lee, Hao
;
Tseng, Chia-Yung
;
Lo, Wen-Tuan
;
Wang, Chieh-Min
In this paper, we demonstrate an attachable energy-harvester-powered wireless vibration-sensing module for milling-process monitoring. The system consists of an electromagnetic energy harvester, MEMS accelerometer, and wireless module. The harvester consisting of an inductance and magnets utilizes the electromagnetic-induction approach to harvest the mechanical energy from the milling process and subsequently convert the mechanical energy to an electrical energy. Furthermore, through an energy-storage/rectification circuit, the harvested energy is capable of steadily powering both the accelerometer and wireless module. Through integrating the harvester, accelerometer, and wireless module, a self-powered wireless vibration-sensing system is achieved. The test result of the system monitoring the milling process shows the system successfully senses the vibration produced from the milling and subsequently transmits the vibration signals to the terminal computer. Through analyzing the vibration data received by the terminal computer, we establish a criterion for reconstructing the status, condition, and operating-sequence of the milling process. The reconstructed status precisely matches the real status of the milling process. That is, the system is capable of demonstrating a real-time monitoring of the milling process.