Gong Jun-Shuai,Wang Zhi-Liang,Qu Hui-Wen,Cang Ding-Yong
A polyimide (PI)-based flexible bandpass filter is fabricated by self-metallization technology, which covers Wireless Local Area Network (WLAN) of 5.15—5.875 GHz. The measured characteristics indicate the flexible filter under flat state has the return loss of better than 20 dB, the minimum insertion loss of 0.83 dB, a 3 dB bandwidth of 0.725 GHz, and the central frequency of 5.5 GHz. At the same time, the designed filter is measured in different bending and folding conditions. Simulated and measured results are similar whether the filter is under flatting, bending, or folding conditions. Fatigue test and timeliness test are studied to confirm that the filter has stable chemical and mechanical properties. The formed silver layers fabricated by self-metallization technology have good mechanical and electrical flexibility. The designed flexible filter is promised for integration within future flexible electronics.
Jian Liu,Weizhong Xu,Zhongwen Kuang,Pengli Dong,Youxing Yao,Huaping Wu,Aiping Liu,Fangmin Ye
Smart hydrogels play a vital role in fundamental research and industrial applications in the fields of biosensors, flexible devices and intelligent human–machine technologies; however, developing a simple, low-cost and large-scale method to obtain hydrogel actuators with rapid response and robust and steadily controllable motion remains a big challenge. In this work, a temperature-responsive, gradient structured hydrogel with quick bending and adjustable actuation was fabricated by the copolymerization of the N-isopropylacrylamide (NIPAM) monomer with dispersed montmorillonite (MMT) via a facile precipitation method. The introduction of MMT with good thermal conductivity made the volume phase transition of the PNIPAM-based hydrogel occur earlier, and the deformation degree and bending direction could be adjusted by changing the MMT content. The representative composite hydrogel with 0.2 g MMT in the precursor presented bidirectional bending characteristics with a bending amplitude of about 289° and an average bending speed of about 36.0° s−1, while the composite hydrogel with 0.3 g MMT in the precursor only possessed a unidirectional bending ability with a bending amplitude of about −259° and a bending velocity of about −28.8° s−1 due to the great difference in the shrinking capacity between the top and bottom sides of the composite hydrogel. In addition, flexibly controllable deformation was specially realized by a well-designed patterned hydrogel with a local component and a thickness difference. Our work provides a practical method for the ingenious design of a hydrogel for further development of programmable and versatile hydrogel-based smart actuators and soft robots.
危险品化学品经营许可证（带存储）