Project 13
Processing and Electronic Properties of 3D Printed PEDOT:PSS Sensors
(dr. kunal kate, ME)
Project Schematic of Processing and Electronic Properties of 3D Printed PEDOT:PSS sensors
Abstract: In recent years, conductive polymers have received extensive research due to their applications in flexible electronics, energy harvesting devices, human-robot interfaces, e-skins, etc. Among these, PEDOT:PSS is arguably the most popular organic conducting polymer due to its conductivity, flexibility, piezoresistivity, and processability in water. Owing to these properties, PEDOT:PSS has also been utilized as a sensing material in tactile sensors. However, available literature shows substantial variation in the performance parameters of PEDOT:PSS based strain sensors depending on the processing conditions, fabrication process, and the substrate used, and such literature is not available for 3D printed PEDOT:PSS strain sensors. For the advancement of PEDOT:PSS as a reliable strain sensing material with 3D printing, it becomes imperative to understand the effect of substrate on the morphology of the films and hence the sensing response behavior of PEDOT:PSS.
We hypothesize that the change in surface texture and porosity created due to the 3D printing process will influence the strain sensitivity of PEDOT:PSS (Figure 1). For this study, the student will 3D print tensile bars with four different polymer substrates, namely TPU, TPE, PLA, and Polyimide (Kapton) and measure their surface roughness, and density. Subsequently, a thin strain gauge pattern of a conductive organic polymer, PEDOT:PSS, will be deposited onto the 3D printed substrates in the gauge length region of the tensile bar with a 3D printing process called direct writing technique. Electrical connection will be made to the two ends of PEDOT:PSS printed pattern and the student will record the change in strain caused due to applied force during tensile testing. From this study, the student will determine a process map to understand the correlation between sensory response, applied strain, time, and mechanical histories for different substrate materials. Additionally, the student will measure surface roughness of these 3D printed tensile samples using a handheld surface profilometer and contact angle measurements to understand the interfacial adhesion behavior between the conductive ink, polymer substrates and the electronic properties of the sensor.
