Functional design of beetle leg joints: morphology, tribology, and cuticular microstructure

• Applicant: Konstantin Nadein, Ph.D.
• Subject Area: Systematics and Morphology (Zoology)
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 414813928

The goal of this research is to reveal and describe tribological, functional, and structural properties of joints in beetle’s legs. The model objects are imagoes of the darkling beetle Zophobas morio and Congo rose chafer Pachnoda marginata. The objectives of the research are: 1. Description of the principal morphological design of joints; 2. Study of the tribological properties of the cuticle of joints (including wear effects); 3. Examination of the contamination resistance properties of the cuticle of joints; 4. Checking the supposed presence of cuticular-based lubrication in joints; 5. Study of the mechanical properties of the cuticle of joints (stiffness, hardness, resilience); 6. Description of the microscale structure of the cuticle in joints and checking of possible presence of reinforcing metals. The research program comprises eight chapters. Chapter 1 represents the general morphological description of primary elements of joints and is the primary descriptive base for the following stages. Chapters 2-8 focus on the selected properties of joints according to the objectives: tribological properties, wear effects, lubrication, contamination resistance, mechanical properties, microscale structure, and elementary composition of the cuticle of joints. The methods of X-ray microtomography, light, fluorescence, scanning and transmission electron microscopy (SEM and TEM), cryo-SEM, confocal laser scanning microscopy, atomic force microscopy, energy-dispersive X-ray spectroscopy, nanotribology and nanoindentation will be used in the course of this research. The expected results of the project will supposedly be a relevant and promising contribution to further biomimetic-oriented studies in a broad range of topics in both engineering and material sciences and promising for a biomimetic transfer in studies of microelectromechanical systems and robotics.

• DFG Programme: Research Grants