The present disclosure relates to a testing device comprising a bracket including a first groove and a second groove parallel to each other, wherein the first groove and the second groove run through an inner surface of the bracket perpendicularly to a thickness direction of the testing device; a plate assembly including a first plate and a second plate parallel to each other, wherein the first plate is disposed within the first groove and fits closely within the first groove along a length direction and a thickness direction of the device, the second plate is disposed within the second groove; a connector array including a plurality of connector assemblies disposed on the plate assembly in a predetermined pattern, wherein each of the plurality of connector assemblies is connected between the first plate and the second plate; and a displacing tool disposed on the bracket and/or the plate assembly and configured to displace the second plate relative to the first plate within the second groove along a length direction and/or a thickness direction of the testing device.