Conceptual Design of Compound‑Eye‑Like Microstructures for Light Environment Regulation in Martian Plantations

Author: Zhang Suhang

               Luoyang, Henan

Abstract

Martian plantations are confronted with multiple challenges, including low total solar irradiance, a relatively high fraction of ultraviolet radiation, dust obscuration, and heterogeneous illumination induced by the low solar elevation angle. Drawing inspiration from the discrete array of small apertures in insect compound eyes, this paper proposes the conceptual scheme of a compound‑eye‑like microstructure light‑regulation layer. The micro‑aperture array spatially partitions incoming light and redistributes peak irradiance. Combined with a diffusion layer, an ultraviolet filtering layer and spectrally selective thin films, the integrated system realizes light homogenization and spectral tuning for plant canopies. This work only discusses light‑environment modulation within the optical band and excludes high‑energy particle shielding as well as pressure‑bearing structures; it is positioned as a conceptual proposal and a pre‑research framework.

1. Problems

The solar irradiance on the Martian surface is approximately 43 % of that on Earth, and the relative proportion of ultraviolet radiation is elevated. Dust events and a low solar elevation angle further produce uneven illumination. In greenhouses or cultivation modules, local light peaks easily emerge at the top of plant canopies while the bottom layers receive insufficient irradiation. Plant growth demands stable photosynthetic photon flux density (PPFD), appropriate red‑blue ratios, far‑red fractions, and controlled UV‑B dosage. Conventional flat transparent covers cannot simultaneously satisfy the requirements for light homogenization, ultraviolet management and spectral matching.

2. Proposed Scheme

The transparent cover of the plantation is designed as a multi‑layer synergistic light‑regulation system:

1. Micro‑aperture array layer: Small‑aperture units spatially split incident light, suppress local irradiance peaks, eliminate intense light spots and improve illumination uniformity over the canopy.

2. Diffusion layer: Converts direct sunlight into diffuse light to adapt to low‑angle incidence and dust‑scattering conditions on Mars.

3. Ultraviolet filtering layer: Selectively attenuates excess UV‑B while preserving and adjusting ultraviolet components with physiological signaling functions.

4. Spectrally selective thin‑film layer: Tuning the ratios of red, blue and far‑red light to match the photoresponse requirements of target crops.

5. Dust‑proof and load‑bearing layer: Independently provides mechanical support and facilitates dust cleaning; this layer also does not perform high‑energy‑particle shielding.

3. Key Performance Metrics

- Average transmittance in the visible band

- Haze and fraction of diffuse light

- PPFD uniformity across the canopy

- Cumulative UV‑B irradiation dosage

- Red/blue ratio and far‑red proportion

- Suppression ratio of irradiance peaks achieved by the microstructure

4. Validation Route

First, ray‑tracing simulations are carried out. Under the same total light‑collection area, the irradiance peak value and light uniformity of the flat cover and the compound‑eye‑like microstructure are compared. Then samples are fabricated for measurement of transmittance, haze and spectral selectivity in the UV‑Vis‑NIR range. Finally, controlled plant cultivation experiments are performed inside a Martian environmental simulation chamber; observables include plant height, biomass, photosynthetic rate and stress biomarkers. A literature review is performed in parallel to distinguish the present design from existing microlens homogenization and greenhouse light‑modulation films.

5. Scope Statement

This concept only achieves optical‑band light regulation. It is not intended to reduce the flux of galactic cosmic rays or solar energetic particles and cannot replace regolith covering, water shielding, mass shielding or magnetic protection. The microstructure layer also bears no responsibility for module pressure resistance or micrometeoroid protection. The proposal supplies a biomimetic microstructure idea for homogenization, ultraviolet control and spectral matching for Martian cultivation systems. Its engineering feasibility shall be verified step‑by‑step via simulation, specimen testing and prototype experiments.