▎ 摘　　要

NOVELTY - A graphic flexible strain sensor preparing method involves performing plasma cleaning of the polydimethylsiloxane flexible substrate and hydrophilizing the substrate, mixing the water-based graphene and absolute ethanol and sonicating, and centrifuging, taking the supernatant to obtain graphene spreading solution. The clean deionized water with a clean surface is prepared, followed by spreading sucked the graphene spreading solution on the surface of the deionized water, transferring the liquid containing the graphene layer to a membrane analyzer, compressing the graphene liquid surface layer, etching the graphene strain layer, pasting the patterned polyimide tape on the treated substrate, fixing at the front end of the dip coating head, placing on a heating platform, peeled off the polyimide tape, dripped the two ends of the graphene strain layer with silver paste electrodes, connected with copper wires, and heat-cured and encapsulated to obtain the finished product. USE - Method for preparing graphic flexible strain sensor. ADVANTAGE - The method enables preparing the graphic flexible strain sensor with high strain capacity and high sensitivity factor in simple and cost-effective manner. DETAILED DESCRIPTION - A graphic flexible strain sensor preparing method involves performing plasma cleaning of the polydimethylsiloxane flexible substrate and hydrophilizing the substrate to make the substrate surface hydrophilic, mixing the water-based graphene and absolute ethanol at a mass ratio of 1:0.5-1 and sonicating for 30 minutes, and centrifuging at a centrifugal speed of 6000 rpm, after 30 minutes, taking the supernatant of the solution to obtain graphene spreading solution. The clean deionized water with a clean surface is prepared, sucked the graphene spreading solution with a clean syringe, followed by spreading it drop by drop on the surface of the deionized water, taking the way of left and right circular drops to keep the surface pressure stable during the dropping process, keeping aside for 15 minutes after spreading, and waiting for the absolute ethanol to evaporate to form a graphene layer, transferring the liquid containing the graphene layer to a membrane analyzer, compressing the graphene liquid surface layer at a compression rate of 2 mN/m per minute to obtain compact graphene solution, utilizing a laser to etch the graphene strain layer with the desired pattern on the polyimide tape, pasting the patterned polyimide tape on the treated polydimethylsiloxane flexible substrate, fixing its flexible substrate at the front end of the dip coating head, setting the descending height of the dip coating head to -20mm, the ascending height to 5mm, the descending speed and ascending speed to be 4mm/minute and the descending residence time to 1 second, vertically pulling the polydimethylsiloxane flexible substrate at a speed of 2-5 mm/minute in the graphene solution to transfer the graphene film to obtain a graphene strain layer transferred to the substrate. The resulting polydimethylsiloxane flexible substrate is placed on a heating platform at 80 degrees C for 5 minutes to remove water carried during the transfer process on the substrate, peeled off the polyimide tape to make a patterned graphene strain layer on a flexible substrate, respectively dripped the two ends of the graphene strain layer with silver paste electrodes, connected with copper wires to wait for the silver paste to solidify, and heat-cured and encapsulated to obtain the finished product. An INDEPENDENT CLAIM is also included for a graphic flexible strain sensor prepared by the method.