Complete Inhibition of Vertical Mosquito Landing through Topographical Surface Design

Abstract

Mosquito-borne diseases such as dengue, chikungunya, and malaria have long been a health and economic burden in our society. Such illnesses develop after the pathogen, here arboviruses, are transmitted to humans by female mosquitoes during blood meals. In the case of dengue and chikungunya, such pathogens are transmitted to humans by infected Aedes aegypti females. Prior to feeding the insects rest on vertical surfaces. In this work, a surface roughness threshold was observed for live Aedes aegypti colonies, and below a root-mean-squared roughness of S q < 0.124 μm the mosquitoes were physically incapable of gripping vertical substrates. This roughness threshold was unaffected by surface wettability or relative humidity. The importance of topographical feature height was understood using a claw-hooking model considering friction. Local defects above this threshold allowed claw hooking to take place, emphasizing the importance of surface uniformity. An antimosquito coating was developed that reduced surface roughness below this threshold when it was applied to realistic surfaces such as wood, brick, wall laminates, and tile. Lowering the surface roughness below the threshold reduced the number of mosquitoes capable of landing on the surfaces by 100%: i.e., no mosquitoes were able to adhere to the treated surfaces. The ability to completely inhibit Aedes aegypti females from landing on surfaces represents a new vector-borne disease control strategy that does not suffer from the nontarget toxicity, resistance, or ecosystem disruption associated with conventional chemical control strategies.

Self-Assembly of Hemimyzon Formosanus-Inspired Crescent-Shaped Nanosucker Arrays for Reversible Adhesion

“…Over 3.6 billion years of natural selection and evolution, living creatures have developed versatile strategies to address diverse survival challenges. By way of illustration, insects and spiders use curved grapnel-like claws and dense tufts of fine bristles on cuticular surfaces to climb and promote attachments through interlocking with rough surfaces. − Instead of microharis, the hierarchical structures of setae and spatulae on gecko feet generate van der Waals forces as they are in intimate contact with a target. , By applying anisotropic directional stresses onto their spatulae, geckos can rapidly switch and control their adhesion strengths for locomotion onto vertical or even inverted surfaces. In sharp contrast to the dry adhesion mechanism, mussels secrete specialized proteins, known as catecholic amino 3, 4-dihydroxyl- l -phenylalanine (DOPA), for clinging to wet surfaces. , The DOPA and its derivatives have demonstrated extraordinarily strong interfacial adhesions as a natural adhesive.…”