Dynamic manipulation of droplets using mechanically tunable microtextured chemical gradients

Materials and strategies applicable to the dynamic transport of microdroplets are relevant to surface fluidics, self-cleaning materials, thermal management systems, and analytical devices. Techniques based on electrowetting, topographic micropatterns, and thermal/chemical gradients have advanced considerably, but dynamic microdroplet transport remains a challenge. This manuscript reports the fabrication of mechano-tunable, microtextured chemical gradients on elastomer films and their use in controlled microdroplet transport. Specifically, discreet mechanical deformations of these films enabled dynamic tuning of the microtextures and thus transport along surface-chemical gradients. The interplay between the driving force of the chemical gradient and the microtopography was characterized, facilitating accurate prediction of the conditions (droplet radius and roughness) which supported transport. In this work, the use of microtextured surface chemical gradients in mechano-adaptive materials with microdroplet manipulation functionality was highlighted. Techniques to alter the surface of materials to enable transport of fluids have advanced considerably, but dynamic microdroplet transport remains a challenge. Here, the authors report the fabrication of microtextured chemical gradients on elastomer films and their use in controlled microdroplet transport.

Automated summary

Materials and strategies for dynamic transport of microdroplets are relevant to various applications such as surface fluidics and analytical devices. Advanced techniques based on electrowetting, micropatterns, and gradients have been developed, but challenges remain in dynamic microdroplet transport. This study highlights the fabrication of mechano-tunable microtextured chemical gradients on elastomer films for controlled microdroplet transport. The interplay between driving forces and microtopography enables accurate prediction of conditions for successful transport.