Critical Drop Sizes for Manipulating Mist with Flexible Fiber Arrays

Critical Drop Sizes for Manipulating Mist with Flexible Fiber Arrays

Princeton Docket # 12-2738

Researchers at Princeton University have developed a method to predict an optimum drop size for retention of liquids in a fibrous material.  The invention can be applied to choose designs used to create drops to spread on or retain in a given fibrous material for different purposes.

Fibrous media are ubiquitous functional and versatile materials. Natural systems such as hair, feathers or adhesive pads, and engineered systems such as nano-textured surfaces or textile products, represent different forms of fibrous media. Current studies of such materials are restricted only to wetting of rigid fibers and the elasto-capillarity effects of such materials.

To address the practical use of spreading liquid drops on a flexible fiber medium, Princeton researchers identified the conditions for a drop to remain compact with minimal spreading or to coalesce a pair of elastic fibers. The optimal volume of liquid represented by a critical drop size can then be determined to avoid such coalescence. Bigger sizes of drops are easily shed from the surface, whereas the critical drop size spreads within and is retained by the fibrous material. This method is applicable to a wide range of fibrous materials.

It is anticipated that this method will have immediate application to consumer products, such as hair sprays, pet sprays, nylon sprays or any fibrous surface spray-on product. It also has application potential in agricultural and gardening spray products, such as herbicide sprays, pesticide sprays, and fertilizer sprays.