| 초록 |
Electronic textiles (E-textiles) have emerged due to the growing interest of wearable electronics. Various electrical components such as interconnects, energy harvesting devices, energy storage devices, transistors and sensors are being developed for numerous applications. Among them, gas sensors are useful for alarming the users for hazardous situations for everyday life and industrial workplaces. Hydrogen gas (H2) is one of the most cleanest and promising energy source, however, the low spark ignition energy (0.02 mJ) and wide flammable range (4~75%) requires accurate and fast leakage detection. In this work, Palladium (Pd)-based fiber-type H2 sensor is proposed. The fiber is stretchable and conductive which changes its conductivity under H2 exposure. The Pd-based conductive fiber is fabricated by a series of solution processes. First, Pd ions are inserted inside the polymer fiber by swelling the fiber using Pd salts dissolved in organic solvents. Then, the Pd ions are chemically reduced into nanoparticles by swelling the fibers with reducing agents. The steps can be repeated to increase Pd nanoparticle concentration and conductivity. The resulting fiber is filled with Pd nanoparticles which forms a conductive network inside the polymer. Pure Pd has a lattice constant of 3.90 Å, but when it is exposed to H2, H atoms are incorporated into the surface of the Pd layer resulting in the formation of a semiconducting Pd hydride (PdHx) with a lattice constant of 4.04 Å. Therefore, when the fiber is exposed to H2, the characteristics of the fiber changes due to PdHx formation. The effect of the synthesis method on the sensor characteristic analyzed. |
