▎ 摘　　要

NOVELTY - A three-dimensional flexible strain sensor optimizing method involves using top surface of a rectangular parallelepiped graphene foam has a through hole having a diameter of 2 mm at the center of the top surface, where the graphene foam is provided with two external electrodes and is taken out by an external wire, and filling the graphene foam with the polymer. USE - Method for optimizing a three-dimensional flexible strain sensor. ADVANTAGE - The method constructs a millimeter-scale hole in the three-dimensional sensitive material, so that the sensitive material has more fragile points, and the structural damage is more likely to occur under the weak strain, causing a significant change of the electrical signal. The process is simple, and the sensitivity optimization of the three-dimensional flexible strain sensor can be realized at a lower cost. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing a three-dimensional flexible strain sensor, which involves opening a through hole having a diameter of 2 mm on the nickel foam, growing a nickel foam having a through hole on the nickel skeleton by a normal pressure chemical vapor deposition method, and the graphene layer has a wall thickness of 1-2 carbon atoms, removing the graphene foam by dilute hydrochloric acid etching to remove the nickel skeleton, when two external electrodes are provided on both sides of the graphene foam, and two external electrodes are led out through the wires, and filling the polymer to obtain the three-dimensional flexible strain sensor.