Tensile testing of freestanding polymer thin films with non-standard geometries

While an increasing requirement from both fundamental and application, a direct tensile testing of freestanding polymer thin films in the air remains a challenge, mainly due to their extreme fragility. This study aims to establish a facile and reliable testing system, and investigate the effect of specimen geometry on the testing. First, a thin film transfer and adhesive guide frame gripping technique is introduced. With low length-to-width ratio specimens, tensile testing of rectangle non-standard polystyrene films with thickness down to 45 nm is achieved on a commercial universal testing machine. By changing specimen width and gauge length individually, a scale law between system compliance and specimen width is then verified. After corrected by compliance, a constant modulus of similar to 3.15 GPa for 45-4319 nm thick polystyrene films can be obtained. This study provides a potential strategy to overcome operational difficulties in performing tensile testing of freestanding polymer thin films.