# Electrospun Nanofibers for Integrated Sensing, Storage, and Computing Applications
## 3 Electrospun Nanofibers in Transistors: Computation and Multifunctional Electronics
### Typical Applications of Nanofiber-Based Transistors
Voltage transfer characteristic (VTC) and a sharp inverter response with a maximum gain (defined as \(-\partial\text{V}_{\text{OUT}}/\partial\text{V}_{\text{IN}}\)) of 11 at V\({}_{\text{DD}}\) = 4 V are shown in Figure 14c,d. This transistor had a good noise tolerance ability and wonderful dynamic behavior of the inverter under an ac square wave signal. Subsequently, transistors with different electrospun nanofibers, such as InGdO, Sr-doped In\({}_{2}\)O\({}_{3}\), Al, Ga, Cr doped In\({}_{2}\)O\({}_{3}\), and IGZO, were put into the resistor-loaded inverter circuit with different operating voltage and gain. Figure 13: Applications of electrospun nanofiber-based transistors. (**a–c**) Structure and electrical characteristics of single PANI nanofiber field-effect transistor: (**a,b**) two different structures of the PANI nanofiber-based device. (**c**) The current response of the FET in real-time for various NH\({}_{3}\) concentrations at V\({}_{\text{G}}\) = 0 V and V\({}_{\text{G}}\) = \(-\)10 V. Reprinted from Reference [80] Copyright 2011 MDPI. (**d**) A schematic illustration of the transistors based on GZO nanofibers and the according to electrical measurement circuits. (**e**) Source-drain current(I\({}_{\text{sd}}\)) of GZO FET as a function of time under exposure to 15% and 85% relative humidity. Reprinted with permission from Reference [81]. Copyright 2012 The Materials Research Society. (**f–j**): single nanofiber transistor based on MEH-PP and its photoluminescence properties: (**f**) Schematic layout of electrospinning process to fabricate single nanofiber-based FETs and the inset image shows the MEH-PPV molecular structure. (**g**) Bright-field and (**h**) fluorescence micrographs of a light-emitting single-fiber-based FET. (**i**) Normalized PL spectra of thin-film (dash-dotted line) and nanofiber embedded in a FET device with V\({}_{\text{DS}}\) = 0 V, and with V\({}_{\text{GS}}\) = 0 V (continuous line) or \(-\)40 V (circles). (**j**) Nanofiber PL spectra for V\({}_{\text{GS}}\)= 0 V (continuous line), \(-\)20 V (dashed line), and \(-\)40 V (dotted line). Reprinted with permission from Reference [82]. Copyright 2010 Royal Society of Chemistry. (**k–n**) Textile-based OFETs with PQT-12:PEC nanofibers with excellent photosensitivity: (**k**) Transfer characteristics of PDMS buffered textile-based phototransistors under light illumination with various wavelengths. (**l**) Real-time photoresponse behaviors under the illumination of monochromatic light with a wavelength of 470 nm (blue) and 670 nm (red). (**m**) Schematic depiction of the manufacturing process of photoimaging arrays (10 \(\times\) 10) of the PDMS-buffered textile-based photosensors. (**n**) Spatial photo-sensing mapping of the textile-based photosensor matrix under light illumination with the star-shaped laser source. Reprinted with permission from Reference [66]. Copyright 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. In conclusion, the combination of 1D materials and transistors offers more chances for the cost-efficient electrospinning method to expand its application field. The number of varied fiber materials, including the majority of organic materials and metal-oxide semiconductors, is not inferior to the kinds of normal film channel materials, and special structures, such as hollow and core-shell fibers, for high-performance FETs have been successfully produced in this simple way. Nanofiber-based transistors coupling electrical, sensing and optical functionalities will play a significant role in innovative electronic devices in the near future and a summary of information on the electrical properties and applications of FETs with different kinds of nanofibers is shown in Table 2.