Electrospun TiO2 nanofibres sensing and memory devices

Titanium dioxide nanofibers were synthesized using electrospinning technique. The nanofibers were porous with average diameter and length ∼150 nm and 200 μm respectively. Humidity and gas sensing devices were fabricated by lithographically defined aluminum electrodes on top of the nanofibers deposited on silicon dioxide grown thermally on silicon substrate. The performance of TiO2 nanofiber humidity sensor was tested by AC and DC electrical measurements at 40% to 90% relative humidity. The response and recovery time was 1 second and 4 seconds respectively between 40% and 90% relative humidity. The sensitivity of the TiO2 humidity sensor in the range of 40 to 90 %RH was 150MΩ/%RH and 20MΩ/%RH at 10 Hz and 100 Hz respectively. The nanofibers also exhibit gas sensing properties as well and its resistances change in nitrogen environment. The excellent sensing characteristics of nanofibers are attributed to porous nature and small diameter of the nanofibers. Further the resistance random access memory (ReRAM) devices were fabricated and analyzed. Initial measurements on nanofiber ReRAM devices show that nanofibers have great potential to be form functional components of such devices. (author)