서강대학교

초록/요약

Major element highly demanded in a current developing field of printing electronics such as display panels, RFID antennas, and solar cells has been electrical conductive ink or paste.[1-3] However for newly rapidly emerging 3D printing referred to the additive manufacturing technique, the deposit conductive material, especially in type of fused deposition modeling (FDM), is non-wet based but in rigid thermoplastic filament format.[4] Furthermore an object is printed in bottom-up forming 3D structure with layer by layer, not in 2D thin absorptive deposition of fluidic ink on a planar substrate for the conventional printing techniques. In this reason it was not so easy to produce a conductive filament in aspect of both fabrication and application. Only a few conductive filaments have developed so far and they are mostly carbon allotrope based, because thermoplastic is relatively easy to be well composited with carbon material as an additive conductive filler, due to their chemical stability and non-oxidation in high temperature and strong binding with polymer.[3, 5-8] For example, in 2012, S. Leigh et al formulated the polylactic acid composite with carbon black mixed with an additive binder of polymorph polycaprolactone, referred to carbomorph, achieving the fairly good conductivity with the line resistance 10 /cm and demonstrated one wearable electrical glove sensor using carbomorph.[4] In commercial market, very recently a few numbers of conductive filaments have been reported based on carbon nanotube and graphene as well as CB. Although research and products have been massively studied and introduced in market to end users, printing application of incorporating conductive filament well into a thermoplastic object did not be reported frequently nor well established, which should be expend widely to open up the comprehensive new field of 3D printing electric and electronics.