Noncontact Parallel Machining of Droplet Structure via Temperature Control

Machining of droplet structure is of great importance and can be applied in a wide range of potential applications in material science, photonics, sensors, pharmaceuticals, and biotechnology. In this work, a low-cost but precise method is proposed for the high-volume production of droplets with monodispersed inner cores that form an ordered structure of the droplet. By simply applying heating or cooling, the surrounding solution can be injected into the host droplet to form its inner cores. The injection is found to attribute to the thermal induced Marangoni effect, where both the injection site and efficiency can be regulated through the introduced temperature gradient. Compared to conventional techniques, the proposed method process droplet structure in a non-contact, bottom-up and in situ manner. As a result, it presents various benefits such as low cost, high productivity, good compatibility and great flexibility.