Mechanics of a Mosquito Bite

Abstract

The objective of this thesis is to provide a fundamental understading of the process of a mosquito bite. Mosquito fascicle, which is the part of the mosquito used for penetrating the skin and drawing blood, is 2mm long and 30 μm in diameter. A needle of this size to be able to penetrate a tough membrane like the human skin needs some kind of stabilization phenomena with which buckling failure can be prevented. By studying high speed video of the process and Scanning Electron Microscope images of the fascicle, a stability mechanism is observed which increases the critical buckling load of the fascicle and prevents failure. This stability mechanism is explained by using the theory of non-conservative force and Beck's column theory. To further support the argument of non-conservative forces, Finite element models of the skin penetration process is built. Since there is no published data on the properties of the fascicle, mechanical tests are conducted to get stress strain data of the fascicle to build the material model used in finite element analysis. The finite element simulations support this concept where the fascicle can only penetrate the skin with the application of non conservative forces.