Transfer printing has emerged as a deterministic assembly technique for moving thin-film semiconductors into desired layouts by using rubber stamps; however, replicating transfer printing for different semiconductors fails to achieve high efficiency, hindering the fast development of flexible hybrid electronics. In this work, a novel transfer printing technique using droplet stamps is developed based on Laplace pressure and surface tension. The working principle is explained by liquid bridge analysis and demonstrated by a 100% yield of transfer printing a batch of thin-film semiconductors with different materials, sizes, and shapes. Besides, the droplet stamps are used in fabricating epidermal hybrid optoelectronics for accurate blood pressure monitoring to verify their high working efficiency. Thus, taking advantage of eliminating Poisson effects and solving the incompatibility with conventional fabrication technologies, this technique will play an enabling role in hybrid integration and high-fidelity fabrication.
Keywords: droplet stamp; hybrid flexible electronics; liquid bridge; transfer printing.