Camber deformation property and fracture strain of flexible film made by polydimethylsiloxane

Polydimethylsiloxane (PDMS) is one of the most commonly used materials in flexible optics, stretchable electronic devices and soft micro robots/actuators. One often-used mechanical ability of PDMS film in these applications is to perform the camber deformation, such as the joint sensor and the flexible imprinting on the non-planar surfaces. The mechanical properties of PDMS film that matter most are relationship between input force and curvature of deformation, and the maximum received curvature that can be achieved before fracture. Therefore, this paper is committed to investigating the camber deformation property and fracture criteria of flexible film made by PDMS. At first, the PDMS films were fabricated with different composition ratio of curing agent and film thickness, which will lead to different mechanical properties. The Young's modulus of each film was precisely measured according to the Hooke's law. Then, the camber deformation property and the fracture caused by overstretch were investigated in a vacuum chamber, and the relationship of maximum received curvature versus the Young's modulus and film thickness was analyzed. At last, the distribution of deformation and strain of the film was calculated by finite element simulation. The simulation and experimental results indicate that the PDMS film will fractured when the maximum shear elastic strain is about 27–32% (mm−1) of film thickness. The research results provide fundamental insights into the mechanical properties and practical instructions for the PDMS flexible films. •Camber deformation and fracture of flexible PDMS film was investigated.•The deformation is depended on the pressure, Young's modulus and film thickness.•The maximum received curvature mainly affected by the film thickness.•The fracture shear strain is about 27–32% (mm−1) of film thickness.