Controlling Nanostructure in Inkjet Printed Organic Transistors for Pressure Sensing Applications

Abstract

This work reports the development of a highly sensitive pressure detector prepared by inkjet printing of electroactive organic semiconducting materials. The pressure sensing is achieved by incorporating a quantum tunnelling composite material composed of graphite nanoparticles in a rubber matrix into the multilayer nanostructure of a printed organic thin film transistor. This printed device was able to convert shock wave inputs rapidly and reproducibly into an inherently amplified electronic output signal. Variation of the organic ink material, solvents, and printing speeds were shown to modulate the multilayer nanostructure of the organic semiconducting and dielectric layers, enabling tuneable optimisation of the transistor response. The optimised printed device exhibits rapid switching from a non-conductive to a conductive state upon application of low pressures whilst operating at very low source-drain voltages (0–5 V), a feature that is often required in applications sensitive to stray electromagnetic signals but is not provided by conventional inorganic transistors and switches. The printed sensor also operates without the need for any gate voltage bias, further reducing the electronics required for operation. The printable low-voltage sensing and signalling system offers a route to simple low-cost assemblies for secure detection of stimuli in highly energetic systems including combustible or chemically sensitive materials.

Material jetting for advanced applications: A state-of-the-art review, gaps and future directions

“…A sensitivity of up to 0.48 kPa − 1 was studied and achieved by Lo et al [255]. Griffith et al reported a highly sensitive pressure detector prepared by inkjet printing of electroactive organic semiconducting materials and the detector was able to convert shock wave inputs rapidly and reproducibly into an inherently amplified electronic output signal [256]. Jeong et al manufactured an electromagnetic pressure sensor by printing conductive patterns on a flexible film [257].…”

A self-powered photodetector through facile processing using polyethyleneimine/carbon quantum dots for highly sensitive UVC detection

“…Moreover, OPDs are solution-processable, and the printable electroactive inks enable large-scale, low-cost manufacture on exible substrates. [21][22][23] More signicantly, human tissue has an approximate average density of 1.10 g cm −3 , with so tissues frequently targeted in medical dosimetry having a density of 1.07 g cm −3 . Thus, the density of thin solid lms made from organic electroactive inks is very similar to that of human tissue.…”

Advanced Algorithm for Reliable Quantification of the Geometry and Printability of Printed Patterns

“…Nanoparticle-based printing and coating methods are essential for the fabrication of flexible electronic devices comprising several patterns, such as lines and shapes, formed from single or multiple layers. The quality and printability of the pattern are crucial factors affecting the outcomes of printed electronics [ 7 , 8 , 9 , 10 ].…”