http://hdl.handle.net/10397/204 Search the Channel search http://repository.lib.polyu.edu.hk/jspui/simple-search http://hdl.handle.net/10397/2536 Title: Polypyrrole-coated fabric strain sensor with high sensitivity and good stability<br/><br/>Authors: Cheng, Xiaoyin; Li, Yang; Tao, Xiaoming; Tsang, Hing-yee Joanna; Leung, Mei-yi; Xue, Pu; Cheng, Xiaoxiang; Yuen, Chun-wah Marcus<br/><br/>Abstract: The sensitivity and stability are mainly factors to hold back the practical applications of Polypyrrole coated fabrics. In this paper, a flexible fabric strain sensor with high sensitivity, good stability and large deformation is reported. It is fabricated by depositing a nano-layer (200nm to 300nm) of polypyrrole on the fabric substrate at low temperature. Thickness andmorphology of the conducting thin film on the surface of the fibers were examined by scanning probe microscopy (SPM) and scanning electron microscopy (SEM). The measurement of the conductivity change with strain shows the fabrics so prepared exhibits a high strain sensitivity of ~160 for a deformation as large as 50%, while its good stability is indicated by a small loss of conductivity after the thermal and humidity aging tests, and supported by the slight change in conductivity and sensitivity over a storage of eighteen months. The flexible strain sensor is expected to be a promising "soft" smart material with good sensing properties in the preparation of smart garment, wearablehardware and biomedical applications.<br/><br/>Description: DOI: 10.1109/NEMS.2006.334708 Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/10397/1662 Title: Leakage field modeling of spiral winding transformer for contactless power converters<br/><br/>Authors: Cheng, K. W. Eric; Lu, Yan; Chan, K. W. Kevin; Kwok, Yi-lin; Kwok, Kin-wing; Kwok, K. F.; Xue, Xiangdang<br/><br/>Abstract: The leakage inductance of the spiral winding transformer is examined. Two dimensional leakage field is modeled and leakage field linkage is then obtained to calculate the leakage inductance. The transformer is an air core based with a separation between the primary and secondary. The application is for contactless power conversion. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/10397/1556 Title: LED lighting development for intelligent clothing<br/><br/>Authors: Cheng, K. W. Eric; Kwok, Kin-wing; Kwok, Yi-lin; Chan, K. W. Kevin; Cheung, C. Norbert; Ho, Y. K.; Kwok, K. F.<br/><br/>Abstract: LED lighting is applied to clothing. It allows a flexible method to provide illumination of lighting. A family of converter topologies is proposed to give this simply method of power conversion. Analysis for the circuits in terms of output power, efficiency and general operation are provided. Two types of LED lighting clothing are developed. One is using super-bright LED embedded on the cloth. This gives active lighting instead of passive lighting. Another one is using optical fibre with grating to form lighting pattern. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/10397/537 Title: Highly conductive flexible transparent polymeric anode and its application in OLEDs<br/><br/>Authors: Wang, Guangfeng; Tao, Xiaoming; Wang, Rongxin<br/><br/>Abstract: Highly conductive flexible transparent polymeric anode was fabricated by inclusion of single-wall carbon nanotubes (SWCNTs) into aqueous poly(3,4-ethylene dioxythiophene: poly(styrene sulfonate) (PEDOT:PSS) system. The transmittance and conductivity of the PEDOT:PSS/SWCNTs anods was studied as a function of the SWCNTs loading. Flexible transparent anode with low sheet resistance was fabricated and organic light-emitting devices fabricated using this PEDOT:PSS/SWCNTs as the anode exhibited a close performance to that obtained using indium tin oxide (ITO) anode. Mon, 01 Jan 2007 00:00:00 GMT