Functional fibrillar interfaces: Biological hair as inspiration across scales.

Hair, or hair-like fibrillar structures, are ubiquitous in biology, from fur on the bodies of mammals, over trichomes of plants, to the mastigonemes on the flagella of single-celled organisms. While these long and slender protuberances are passive, they are multifunctional and help to mediate interactions with the environment. They provide thermal insulation, sensory information, reversible adhesion, and surface modulation (e.

Trichoid sensilla on honey bee proboscises as inspiration for micro-viscometers.

Sensing physical properties of liquids, such as viscosity, is of great significance for both biological organisms and industrial applications. For terrestrial organisms feeding on liquids, such as honey bees that forage nectar, sensing viscosity may help to determine the quality of food sources. Previous experiments showed that honey bees exhibit strong preferences for less viscous nectar; however, the physical mechanism underlying how they perceive viscosity remains unexplored.

Feeding behavior of honey bees on dry sugar.

The feeding habits of insects can be influenced by food abundance, nutrition, physical forces, and many other variables, which is why this topic is multidisciplinary and perennially fascinating. Although honey bees primarily feed on liquid nectar, they also can feed on dry sugar; however, the feeding mechanism for feeding on dry substances by a primarily fluid-feeding insect remains unexplored. We observed that, when honey bees are accessible to both dry sugar and liquid nectar, they prefer to feed on the latter.