Adhesion Force Modeling of Octopus-like Stamp for Micro Transfer Printing

With the rapid advancement in flexible electronics, the micro transfer printing technology is emerging as a highly promising approach for integrating micro/nano-scale heterogeneous materials in this field. A crucial aspect of micro transfer printing research revolves around studying the stamp’s controllable adhesion force, which serves as the execution device for the printing process, so it is necessary to establish an accurate adhesion force model of the stamp. In this study, we have developed a groundbreaking octopus-inspired stamp featuring both cavity and micro-channels. The adhesive force exhibited by the developed stamp arises from the combined effects of van der Waals forces at the stamp's end face and an additional adhesion force resulting from the pressure differential between the cavity and the surrounding atmosphere. The additional adhesion force of the stamp is modeled based on the fundamental principles of fluid dynamics, specifically the Navier-Stokes equation, and the first law of thermodynamics. The numerical computation of adhesion force is carried out by numerical iterative algorithm, and the effects of stretching distance and velocity on the additional adhesion force of the stamp are investigated. The numerical computation results show that the additional adhesion force of the stamp can be controlled by both the stretching distance and stretching velocity. This finding opens up new avenues for optimizing the design of octopus-like stamps used in micro transfer printing.