Preparation And Performance Of High Elastic Circuit Based On 3D Printing Template Method

Flexible electronic is a technology for making flexible circuits by attaching metal or electronic components to flexible substrates.It has good ductility and flexibility.It has broad application prospects,and is a research focus in the field of electronics manufacturing.At present,the traditional conductive inks used in flexible electronic manufacturing are mainly nano-metal,organic metal and carbon-based conductive inks,but they are not conductive themselves.After printed on the substrate,they need to go through a series of post-process,the conductive filler is formed into a stable and continuous film to have conductivity.In contrast,liquid metals such as gallium-based and bismuth-based alloys are very ideal conductive ink materials because they have good electrical conductivity without processing and have good melting and shaping capabilities at room temperature.However,liquid metal's high surface tension and low adhesion to many substrates limit its application on flexible circuits.Therefore,for better use of liquid metal to make flexible circuits,it is still necessary to seek a more convenient and efficient manufacturing method.Based on these,this paper selects liquid metal-gallium indium eutectic(EGaIn)and highly elastic platinum-catalyzed silicone rubber(Ecoflex)as the conductive and substrate materials for making flexible circuits,and proposes a new flexible circuit preparation method-the sacrifice of 3D printed template by internal cleaning,and finally we realize flexible circuit with high flexibility,stability and sensitivity.In this work,the liquid metal-EGaIn high-elasticity circuit was designed and prepared.The hollow ABS circuit model was printed with a 3D printer and placed in the Ecoflex substrate.The model was cleaned and dissolved with acetone to form a microchannel in the Ecoflex for subsequent injection of liquid metal-EGaIn.And by using ion sputtering technology to deposit metal on the surface of Ecoflex,we complete the surface modification of the substrate and improve the wettability of liquid metal-EGaIn on Ecoflex,improving the success rate of injecting liquid metalEGaIn into the channel.We put the prepared liquid metal-EGaIn flexible circuit under deformations such as stretching,bending,torsion and compression,measured and analyzed the changes in circuit performance,and summarized the law of change in circuit resistance during stretching,bending,and torsion.It is found that the prepared circuit can achieve 1000 cycles under 100% strain stablily,and can even stretch to600% strain.We also explored the influence of circuit size,circuit pattern and Ecoflex layer thickness on the sensitivity of the pressure sensing circuit,and achieved fullscale high-sensitivity pressure detection,with a minimum pressure change of 100 mg.Finally,the application of human pulse measurement is completed based on the circuit performance test results.This subject proposed and realized a new liquid metal-EGaIn flexible circuit preparation method,which has good stability and high sensitivity,provides new ideas for the manufacture of liquid metal flexible circuits,and has broad application prospects in flexible sensors and other fields.