Applications Study On 3D Printing Stretchable Conductors For Flexible Electronics

Compared with conventional rigid electronics,flexible electronics have the advantages of small size,lightweight,and tolerance for large deformation,allowing them to accustom to complex and harsh application scenarios.It is foreseeable that they will play a crucial role in feature promising applications like artificial intelligence,to be specific,such as wearable electronics for human-machine interface(HMI),electronic skins,soft robotics,flexible displays,etc.Nonetheless,as an indispensable component of flexible electronics,the flexible,stretchable conductors have encountered problems such as being prone to mechanical damage,signal drift,and complicated manufacturing process,hindering their further applications.To address these problems,the introduction of hydrogen and coordination bonds in matrix materials will significantly improve the tolerance for mechanical damage.It is well-accepted that these dynamic interactions can be reversibly self-assembled endowing stretchable conductors with inherent healability,simultaneously,there will give rise to signal hysteresis due to the accompanying reduction of resilience.Currently,the existing preparation methods for high-performance flexible electronics involving stretchable conductors are almost under the disadvantages of a complicated process,enormously limiting the customized design and further development of flexible electronics.Overall,it remains a challenge to fabricate stretchable conductors with great conductivity,high stretchability,and low hysteresis of the electrical signals.Herein,a UV-curable elastomer resin with high stretchability,great resilience and low hysteresis was developed.Assembling the 3D printed model utilized developed resin with conductive materials,we prepared a stretchable conductor,and further insight into its practical applications in flexible electronics.The main works as follow:(1)A UV-curable elastomer with a novel dynamic hierarchical crosslinking network was investigated that can be stretched up to over 800%and rapid recoverability at 300% strain without prominent elastic fatigue,which is of great significance to the real-time transmission of electrical signals in flexible electronics.The elastic modulus and the maximum strain of the elastomer are tunable by adjusting the proportion of each component to suit the requirements of different application scenarios.(2)Fourier transform infrared(FTIR)spectra and X-ray diffraction(XRD)were utilized to verify the dynamic hierarchical cross-linking network in elastomer and provided deeper insight into the tunable mechanical properties mechanism of dynamic hierarchical cross-linking network for the elastomer.(3)We demonstrated a hydrogel-elastomer assembling methodology based on DLP(Digital Light Processing)3D printing technique to simplify the manufacturing process of stretchable conductors.The prepared stretchable conductor exhibited a good conductivity and elasticity.(4)The stretchable conductors served as a strain sensor exhibiting excellent stability and repeatability after 10 cycles at 20–50% strain with low signal drift and hysteresis.Moreover,the strain sensor could be utilized in recognizing the different bending angles of the finger,making DLP printing of conductive elastomer a viable strategy for the rapid manufacturing of flexible electronics with promising application potential in flexible electronics and soft robotics.(5)Finally,the utilization of liquid metal(LM)to prepare stretchable conductors provides a manufacturing solution for stretchable flexible displays based on 3D printing.The result shows that the stretchable flexible display could maintain work well under various strains.