Effect of sample treatment on biomechanical properties of insect cuticle

Abstract

Due to experimental restrictions it is not always possible or practical to perform biomechanical measurements on fresh arthropod cuticle samples. Hence, in many cases a short- or long-term sample storage is required. So far, it is not known whether any of the standard lab-techniques commonly used to fix or store insect cuticle samples in any way affects the biomechanical properties of the respective samples. In this paper we systematically address this question for the first time, with a focus on practical, easily accessible and common lab-methods including storage in water, ethanol, glutaraldehyde, freezing and desiccation. We performed a comprehensive and sensitive non-destructive Dynamic Mechanical Analysis (DMA) on locust hind leg tibiae using a three-point-bending setup. Our results show that from the tested treatments, freezing samples at -20°C was the best option to maintain the original values for stiffness and damping properties of insect cuticle.