Mechanical model of electromagnetic-assisted transfer-printing stamp containing a four-prism cavity

Abstract

Transfer printing is a key step in the preparation of flexible and stretchable electronic devices, whereas the key to the transfer printing is to control the interfacial force between the stamp and device. In this study, a stamp containing a four-prism cavity for electromagnetic-assisted transfer printing is proposed and a mechanical model of the stamp is established. The magnetic film in the upper part of the stamp is deformed under the action of alternating electromagnetic field. Then, the deformation of upper film is transferred to the flexible film in the bottom part through the liquid in the four-prism cavity so as to change the pressure in the opening cavity at the bottom of the stamp and control the interfacial force between the stamp and device. Mechanical analysis shows that the value of the pressure change at the cavity opening at the bottom during transfer printing increases with increasing electromagnetic driving pressure, but decreases with increasing elastic modulus and thickness of the upper and lower films, as well as with increasing side-length ratio between the upper and lower films. The smaller the film side-length ratio, thickness, and modulus, the more favorable the transfer printing.