Gallium-based Liquid Alloy Printing For Curved Surfaces And Applications Of Plant-based Electronics

Possessing excellent flexibility,stretchability and biocompatibility,flexible electronics have developed novel applications for adapting curved surfaces and plant-based electronics.Compared with solid conductive materials,gallium-based liquid alloy is liquid at room temperature and has the characteristics of fluidity,deformable shape,excellent electrical conductivity and non-toxicity,showing unique advantages in flexible electronics.Current flexible electronics are developed with the trend of being flexible,dynamic,conformal on complex curved surfaces,wireless and organism-integrable.However,there are still many gaps in the existing liquid alloy patterning techniques in these aspects.And it is urgent to explore the patterning methods and applications of liquid alloy in such scenarios to break through the bottleneck of practical application.Targeted for the above challenges,this dissertation realizes universal printing and integration of Galinstan liquid alloy from simple planes to complex curved surfaces,from static to dynamic objects,from inorganic materials to organic plants,and from attachable to unattachable surfaces.And multiple applications are presented.The main research contents and innovations are introduced as follows:(1)Dynamically conformal mask printing of liquid alloy.An ultra-soft,stretchable,adhesive dynamic conformal mask with excellent consistent conformality on 3D curved surfaces is fabricated by regulating the PDMS crosslinking.And a conformal mask printing process for dynamically changing surfaces is proposed.The printing process can adapt to the dynamic changing of objects during and after printing,and the patterned liquid alloy provides epidermal sensing and heating function.Applications of the steering wheel detection of driving modes,model face heating,wireless induction heating and switch control are demonstrated,proving the surface sensing and function integration of liquid alloy.(2)Liquid alloy-based hydroprinting.The adhesion of liquid alloy to wetted plant surface is discovered and the adhesion principle of liquid alloy is explored.Then a liquid alloy hydroprinting process is proposed,in which high-energy liquid is used to adhere liquid alloy on the surface of the plant.And the liquid-alloy-based morphing electronics,which are mild in process,conformal on surface shape,morphology pinning and stress-free,are integrated on living plants.Liquid alloy morphing electronics can monitor the plant growth signals and guide the growth of individual/group plants,providing an effective tool technology for plant research and bio-hybrid robotics research.(3)Liquid alloy wetting enhancing strategy on the super-hydrophobic lotus leaf.Aiming at the waxy layer and micro-nano structure on the surface of superhydrophobic lotus leaf,a liquid alloy wetting enhancing strategy based on surfactant solution is proposed.The intermediate surfactant solution changes the contact model between the liquid alloy and the lotus leaf,and improves the surface energy of the mixed interface to realize the patterning of the liquid alloy.Also,this method is universal for a variety of plants.Further,a plant hybrid sensing system with lotus leaf as the substrate is demonstrated,and then it is applied as a home intrusion prevention.This work broadens the application scope of liquid alloy in plants and realizes the practical implementation of liquid alloy plant hybrid electronics.