Namib Desert Beetles as Bioinspiration for Planetary Exploration

One of the biggest challenges of planetary exploration is the variety of extreme environments that can be encountered, which include extreme thermal fluctuations, radiation and physical corrosion [1, 2]. When different extreme conditions occur simultaneously or in close succession during exploration, the impacts on design can be significantly escalated [2]. Although different technologies for the mitigation of extreme environments are currently available [1], further advancement in planetary exploration will require the development of novel technical solutions that cope with multiple extreme conditions at once. Desert ecosystems are obvious analogues for planetary environments [3]. Despite the harsh nature of deserts, several organisms have evolved physiological, morphological, and behavioural adaptations to survive in these environments. By examining the evolutionary adaptations which meet the multifunctional demands of desert environments, the insights gained can be used to make technology adaptive for extreme environment exploration on planetary bodies.

Project overview

Darkling beetles (Tenebrionidae) of the Namib Desert inhabit one of the hottest and driest places on Earth [4]. These diurnal, flightless beetles seem to have evolved a number of solutions to survive the extreme conditions imposed by desert environments. Although much research to date has focussed on their fog-harvesting behaviour [5, 6], Namib Desert beetles are likely to possess numerous other morphological adaptations, including structural optical whiteness [7, 8], toughening mechanisms [9, 10] and distinct thermal properties [11]. In addition, Namib Desert beetles are some of the fastest insects on the planet, hence, their elytra – the modified, hardened forewings – might not only have excellent mechanical, optical and thermal properties, but also be extremely light-weight in nature.

The aim of the study is to provide novel insight into the multifunctional nature of Namib Desert beetle elytra. The anticipated outstanding properties of the elytra are a promising candidate for application in extreme environments. The goal of the study is twofold. Firstly, to investigate how the structure of Namib Desert beetle elytra is adapted to life in extreme environments by providing a detailed morphological characterization and its associated mechanical, thermal, chemical and optical properties. Secondly, to unravel the physical principles underlying the biological multifunctionality of Namib Desert beetle elytra and investigate whether these principles can be replicated, in part, or in their entirety, and be adapted for use in planetary exploration.

References

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[2] Kolawa E., Mojarradi M. & Del C.L. (2012), “Extreme environments in NASA planetary exploration,” in Extreme Environment Electronics, vol. 42, pp. 11–22. USA: CRC Press.

[3] Rothschild L.J. & Mancinelli R.L. (2001). Life in extreme environments. Nature 409, 1092-1101.

[4] Steckel J. et al. (2010). A preliminary molecular phylogeny of the Namib Desert darkling beetles (Tenebrionidae). African Zoology, 45, 107-114.

[5] Hamilton W.J. & Seely M.K. (1976). Fog basking by the Namib Desert beetle, Onymacris unguicularis. Nature 262, 284-285.

[6] Nørgaard T. & Dacke M. (2010). Fog-basking behaviour and water collection efficiency in Namib Desert Darkling beetles. Frontiers in Zoology 7, 1-8.

[7] Rivera, J. et al. (2020). Toughening mechanisms of the elytra of the diabolical ironclad beetle. Nature 586, 543-548.

[8] Rivera J. et al. (2021). Structural design variations in beetle elytra. Advanced Functional Materials 31, 2106468.

[9] Vukusic P., Hallam B. & Noyes J. (2007). Brilliant whiteness in ultrathin beetle scales. Science 315, 348-348.

[10] Burresi M. et al.(2014). Bright-white beetle scales optimise multiple scattering of light. Scientific reports 4, 1-8.

[11] Shi N.N. et al. (2015). Keeping cool: Enhanced optical reflection and radiative heat dissipation in Saharan silver ants. Science 349, 298-301.