Stretchable Transistor Based On Conjugated Polymer Vertical Layered Composite Film

Demand for wearable and implantable devices is growing rapidly.Stretchable devices ensure the comfort,fit,and longevity of wearable and implantable devices,so its implementation is critical.Compared to traditional silicon-based materials,conjugated polymers are receiving more and more attention due to their solution processing,relatively low modulus?E?and highly adjustable chemical structure.In this paper,a composite film of vertical double-layer structure prepared by blending poly-3-hexylthiophene?P3HT?with styrene-isoprene-styrene triblock copolymer?SIS?was studied and applied to stratchable the transistor.The work is as follows:?1?Research on P3HT/SIS vertical layered composite film.A blended solution of P3HT and insulating polymer SIS was spin-coated onto a high surface energy substrate,and a vertical double-layered composite film with P3HT enriched at the top and SIS deposited at the bottom was obtained by surface induced vertical phase separation.A semiconductor layer and an insulating layer of the organic thin film transistor.The phase structure of the composite membrane was controlled by changing the content of P3HT in the composite membrane.The results showed that when the concentration of P3HT was0.25 mg/mL?composite membrane P3HT-0.25?,P3HT was spread on the surface of the SIS matrix to form a continuous upper surface.The ultra-thin film with a rough interface has a thickness of about 3.91 nm,and the field effect performance is best under this ratio,and the average mobility of 1.0×10^-2 cm²V^-1s^-1 is obtained.In addition,the field effect properties of the composite film show better uniformity and repeatability.Providing a simple and efficient method to obtain a stretchable semiconductor and insulating layer in one step provides the possibility of fabricating a stretchable transistor.?2?Field effect performance of P3HT/SIS composite film under tensile state.The field effect performance of the organic thin film transistor device of the composite film under different tensile strains was studied by transferring the composite film to the surface of the elastomer.The test results show that the composite film exhibits high tensile strength.When the composite film P3HT-0.25 is applied with a tensile strain of less than50%,no crack is formed,and the change of mobility???does not change significantly.When a tensile strain of 100%is applied,microcracks appear,and?decreases by 84.5%?relative to the unstretched state?.The cyclic tensile test results showed that the composite film P3HT-0.25 was stretched 200 times at 50%strain and no crack was observed.The?showed a slight decrease after the first few cycles of stretching,and then remained stable.The tensile resistance of the P3HT/SIS composite film is attributed to the formation of a P3HT/SIS vertical layered pleated interface and an ultra-thin P3HT semiconductor layer formed by blending phase separation.?3?Preparation and performance study of a stretchable transistor based on P3HT/SIS composite film.A preparation scheme for a stretchable transistor suitable for a P3HT/SIS composite film was designed.A stretchable transistor device was prepared using a stretchable electrode in which an elastomer and a metal were combined as a source and drain electrode,a gallium indium liquid metal?EGain?as a gate electrode,and a composite film P3HT-0.25 as a semiconductor layer and an insulating layer.When the tensile strain is not applied,the?of the stretchable transistor is 1.3×10^-2 cm²V^-1s^-1.The stretchable transistor has a decrease in?when a tensile strain of less than 50%is applied,but the drop is controlled within an order of magnitude,and when the strain is released,?is recovered.