Pyroelectric Crystal For Loss-Free Manipulation Of Liquids

Manipulating buffers and organic solvents on surfaces is fundamental for many biological and/or chemical operations and thus critical in various thermal, optical, and medical applications. For any of these, it is necessary to design a platform that enables locally addressable fluids to be navigated with a low loss rate and partitioned and merged in a readily controlled manner. Researchers present a previously unidentified approach by simply stacking three homogeneous layers—a photothermal film (graphene-doped polymer), a pyroelectric crystal (lithium niobate wafer), and a superomniphobic surface (silica nanosphere network)—that work in concert to enable loss-free operations of even ultralow–surface tension fluids with a single beam of light.

The photothermal film is composed of graphene-polymer composite, which senses the light stimuli and responses by generating localized and uneven thermogenesis. Consequently, the pyroelectric crystal converts the heat into extra electric charges, forming a wavy dielectrophoretic force profile that can trap, dispense, and split fluids.

With a single beam of light serving as the stimuli, the technique can remarkably perform all four fundamental operations (movement, merging, dispensing, and splitting) of various liquids in a well-controlled and loss-free manner, without the need of complicated electrodes and high-voltage circuits. The approach has great potential in substantially advancing vast fields, microassays, medical diagnosis, and droplet-enabled manufacturing and engineering.

Read more