The document summarizes an experiment conducted to test the use of palladium nanoshells as hydrogen sensors. Fibers with an average diameter of 250nm were coated with palladium using sputtering to create nanoshells. The nanoshells were introduced into a chamber where their resistance was measured as hydrogen and argon gases flowed through. Results showed the resistance changed with the introduction of 1% hydrogen gas, indicating the palladium nanoshells could effectively be used as hydrogen sensors.

1. University of Puerto Rico<br />Cayey Campus<br />Jessica Díaz Rivera<br />Prof. Elena Gonzalez<br />RISE Program<br />Paragraph 8: Nanotechnology<br /> Nanotechnology refers to the manipulation of the physical and technical characteristics of systems about 100 nm or less in size. R and D nanotechnology aims at understanding and creating improved materials, devices and systems that exploit these new properties. The objective of the experiment that we are to conduct in this lab is to see how the sensor reacts with the addition of hydrogen gas. We started the experiment using electrospinning because this makes the process particularly suited to the production of fibers using large and complex molecules. The fibers with an average diameter of 250nm were coated with Pd deposited by dc magnetron sputtering. Later we carried out the sputtering process that created nanoshells of Pd on top of the fibers. These nanoshells are denser and thicker in the middle and with a gradient toward the edges. We evaluated nanoshells on top of polymer with thickness as a hydrogen sensor. That sample we introduced into a small stainless steel chamber. The flow of Argon and Hydrogen was controlled by individual MKS flow controllers, and the resistance of the sample was measured using a computer controlled Keithley 2400 sourcemeter. The sensitivity of the material was measured as the relative change in resistance. The results of introducing 1% of H2gas into the flowing gas of the chamber indicate that the nanoshells can be effectively used as a sensor. At the end, we proved with a computer program that the nanoshells was effectively if they are used as a sensor.<br />