Insects use hairy or smooth adhesive pads to stick almost all known surfaces. Although studied for more than 300 years, the principles of insect adhesion are still not fully understood and explaining them challenges biologists, physicists engineers. Today we know that contact between organs substrate is mediated via nanometre- thin films fluid. This fluid helps increase pad's area on rough surfaces its special rheology combines capillary with resistance against sliding. We summarize recent...

During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions cycles. Defects in micrometre thin membranes or veins may reduce insect’s flight performance. How do insects prevent crack related material failure their what role does characteristic vein pattern play? Fracture toughness is parameter, which characterises material’s resistance propagation. Our results show that, compared other body parts, hind wing membrane migratory locust S....

Insect cuticle is one of the most common biological materials, yet very little known about its mechanical properties. Many parts insect exoskeleton, such as jumping legs locusts, have to withstand high and repeated loading without failure. This paper presents first measurements fracture toughness for using a standard engineering approach. Our results show that in locust hind 4.12 MPa m(1/2) decreases with desiccation cuticle. Stiffness strength tibia were measured buckling cantilever bending...

Insect wing veins are biological composites of chitin and protein arranged in a complex lamellar configuration. Although these hierarchical structures found many ‘venous wings' insects, very little is known about their physical mechanical characteristics. For the first time, we carried out systematic comparative study to gain better understanding influence microstructure on characteristics damping behaviour veins. Morphological data have been used develop series three-dimensional numerical...

So far, all previous attempts to apply nanostructures for perfect transmission have not achieved maximum transmittance beyond 99.5% due the limited regularity of nanoscale surface geometry: too low many high-end applications. Here we demonstrate a nanostructured stealth surface, with minimal reflectance (<0.02%) and maximal (>99.8%) wavelength range, covering visible near-infrared. Compared multilayer thin film coatings near-infrared applications our antireflective surfaces operate within...

Abstract The cuticle exoskeleton plays a key role in facilitating the evolutionary success of insects. Since mid last century, many different biomechanical properties exoskeletons have been investigated, always utilizing most sophisticated scientific methods available at time. So far, information on seems to be as diverse used measure them. As consequence, insect is often considered exhibit complex and any biological material. However, it remains unclear which respective measurement sample...

Many insects cling to vertical and inverted surfaces with pads that adhere by nanometre-thin films of liquid secretion. This fluid is an emulsion, consisting watery droplets in oily continuous phase. The detailed function its two-phasic nature has remained unclear. Here we show the pad emulsion provides a mechanism prevents from slipping on smooth substrates. We discovered it possible manipulate adhesive secretion vivo using polyimide substrates selectively absorb component. While thick...

If an insect is injured, can it repair its skeleton in a manner which mechanically strong and viable? Previous work has described the biological processes that occur during of cuticle, but until now, there been no biomechanical assessment repaired area. We analysed biomechanics injury process desert locust (Schistocerca gregaria). show after incision, healing occurred almost doubled mechanical strength tibial restoring to 66% original, intact strength. This by targeted cuticle deposition,...

Insect adhesion is mediated by thin fluid films secreted into the contact zone. As amount of affects adhesive forces, a control secretion appears probable. Here, we quantify for first time rate in pads cockroaches and stick insects. The volume footprints deposited during consecutive press-downs decreased exponentially approached non-zero steady state, demonstrating presence storage volume. We estimated its size influx it from simple compartmental model. Influx was independent step frequency....

The flight performance of insects is strongly affected by the deformation wing during a stroke cycle. Many therefore use both active and passive mechanisms to control their wings in flight. Several studies have focused on kinematics, plenty known about mechanism deformability. However, given small size vein-joints, accurate direct mechanical experiments are almost impossible perform. We developed numerical models perform comparative comprehensive investigation behaviour vein-joints under...

Insect cuticle is a biological composite with high degree of complexity in terms both architecture and material composition. Given the complex morphology many insect body parts, finite-element (FE) models play an important role analysis interpretation biomechanical measurements, taken by either macroscopic or nanoscopic techniques. Many previous studies show that nanoindentation measurements this layered very challenging. To develop accurate FE models, it particular interest to understand...

Summary Many parts of the insect exoskeleton experience repeated cyclic loading. Although cuticle insects and other arthropods is second most common natural composite material in world, so far nothing known about its fatigue properties, despite fact that undoubtedly limits durability body vivo. For first time, we here present experimental data cuticle. Using force-controlled loading, determined number cycles to failure for hind legs (tibiae) wings locust Schistocerca gregaria, as a function...

Many arachnids possess adhesive pads on their feet that help them climb smooth surfaces and capture prey. Spider gecko adhesives have converged a branched, hairy structure, which theoretically allows to adhere solely by dry (solid-solid) intermolecular interactions. Indeed, the consensus in literature is spiders smooth-padded relatives, solifugids, without aid of secretion.We investigated contact zone living spiders, solifugids mites using interference reflection microscopy, detection thin...

The geometrical similarity of helicoidal fiber arrangement in many biological fibrous extracellular matrices, such as bone, plant cell wall, or arthropod cuticle, to that cholesteric liquid mesophases has led the hypothesis they may form passively through a mesophase precursor rather than by direct cellular control. In search evidence support refute this hypothesis, here, we studied process cuticle formation tibia migratory locust, Locusta migratoria, where daily growth layers arise...

This paper addresses the question of strength and mechanical failure in exoskeletons endoskeletons. We developed a new, more sophisticated model to predict bones other limb segments, modelled as hollow tubes radius r thickness t. Five modes were considered: transverse fracture; buckling (of three different kinds) longitudinal splitting. also considered interactions between modes. tested hypothesis that evolutionary adaptation tends towards an optimum value r/t, this being which gives highest...