Work

Dynamic mechanical analysis reveals reversible thermal effects in insect tibial cuticle

Year: 2026

Type: article

Abstract: The mechanical performance of insect cuticle arises from its composite structure of chitin fibres embedded in a protein-rich matrix. While chitin contributes to thermal resistance and structural integrity, the protein component is temperature-sensitive and modulates viscoelastic behaviour. Here, we investigated how thermal exposure affects the mechanical properties of tibial cuticle in Locusta migratoria, using dynamic mechanical analysis (DMA) across a temperature range (22–74 °C) and following prior heating to 60 °C or 70 °C. Both storage and loss moduli decreased significantly with increasing temperature by approx. 64% respectively 42%, consistent with partially reversible thermal softening. After re-cooling, the loss modulus increased again to control levels, whereas the storage modulus remained significantly reduced. Tan δ increased significantly with increasing temperature by approx. 31% and remained higher in pre-heated samples, reflecting a shift toward more compliant and dissipative behaviour. No significant differences were detected between the 60 °C and 70 °C treatments. These results suggest that thermal exposure induces reversible changes in matrix protein mobility and non-covalent interactions, affecting stiffness more strongly than damping. The cuticle thus exhibits partial recovery of mechanical function after heating, which may reflect an adaptive response to transient thermal stress. • Dynamic mechanical analysis reveals temperature-dependent changes in locust tibial cuticle. • Heating to 60 °C or 70 °C causes reversible reduction in stiffness but persistent increase in damping. • Loss modulus fully recovers after cooling, suggesting reversible viscoelastic adaptation. • Changes likely result from reversible alterations in matrix protein interactions. • Thermoresponsive cuticle mechanics may help maintain leg function under environmental heat stress.

Source: Journal of the mechanical behavior of biomedical materials/Journal of mechanical behavior of biomedical materials

DOI: 10.1016/j.jmbbm.2026.107450

Authors: Hannah Felicitas Kuhn, Jörg Müssig, Jan-Henning Dirks

Institution: Hochschule Bremen

Language: English

Topic: Advanced Materials and Mechanics

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,690

Funder: Deutsche Forschungsgemeinschaft