LAUSR

Multifunctional functional composite filaments containing conductive fillers are 3D printable, and it permits the fabrication of customised conductive shapes and sensors through Fused Deposition Modelling (FDM). In the present work, FDM printed conductive PLA-Carbon Black (CB) sensors are tested for its solvent sensing ability. Variations happening in the resistance of the sensor upon exposure to solvent are utilised for studying the sensitivity. The impact created by the various thickness and infill density of the 3D printed sensor upon its sensing ability is analysed. Solvents adopted for investigating sensing ability are acetone, chloroform, ethyl acetate, ethanol, dichloromethane, and tetrahydrofuran. The resistance of the sensor found to increase during the dipping stage and reduces while drying cycle. Reduction in thickness and infill density of the sensor improves its sensitivity. Sensors with a thickness of 0.4mm and 2mm with 40% infill density demonstrated higher sensitivity. 3D printed PLA-CB solvent sensor showed sensitivity in the order of dichloromethane > chloroform > tetrahydrofuran > acetone > ethyl acetate > ethanol. The strength of PLA-CB samples decreases because of dipping in the solvent. However, the dipping time required for sensing of the solvent is very minimal (30sec). Hence, the changes happening in the mechanical characteristics of the sensor during the sensing stage does not impart the sensitivity of the sensor significantly. Thus, the 3D printed PLA-CB sensor is suitable for solvent sensing.