The effect of surface tension on the adhesion performance of nanoscale fibrillary structures——a theoretical prediction

The last decade witnesses the thorough investigation of bio-inspired nanoscale fibrillary structures with strong adhesion to stiff substrates. In the present study, we explore the effect of surface tension on the adhesion behavior of a rigid nanoscale fiber and an elastic substrate. With the existence of surface tension, we reconsider the optimal shape of the fiber, critical condition for spontaneous adhesion, saturation of adhesion strength and flaw-tolerant capability. The results indicate that the critical fiber radius for spontaneous adhesion and threshold value for crack size can be significantly enhanced due to surface tension. Meanwhile, the adhesion strength can approach the maximum value faster with fiber radius decreasing ascribed to surface tension, compared with the situation with the absence of surface tension. These conclusions present an inspiration for the optimization of adhesion strength of fibrillary surfaces.