  Sessile drying droplets in various bio-relevant systems, encompassing passive
bio-colloids like DNA, proteins, and blood to active microbes, gain
considerable attention due to intricate interplay among different convective
flows, droplet pinning, mechanical stress, wettability, and the emergence of
distinctive patterns. Chlamydomonas reinhardtii, or chlamys, is a versatile
algal model employed in molecular biology research and spanning diverse
biotechnological realms. While chlamys are harnessed at single-cell and
population levels, their exploration in the context of drying sessile droplets
remains limited. This paper illuminates the multifaceted potential of chlamys,
delving into motility-nutrient interactions and their role in emergent
morphological patterns. The interplay of two competing stressors -- localized
nutrient scarcity and mechanical stress during drying -- is investigated.
Irrespective of these stressors, the global mechanical stress fails to induce
any cracks during the drying process. Interestingly, the reverse ``coffee-ring
effect" is predominantly observed in the non-motile chlamys in the presence of
local nutrients whereas the nutrient depletion prompts local stress in motile
chlamys, culminating in cooperative aggregation and cluster formation.
Furthermore, the quantitative image processing technique leverages textural
statistics to classify the patterns into four classes, motile+with nutrients,
motile+without nutrients, non-motile+with nutrients, and non-motile+without
nutrients, with five distinct drying stages -- Droplet Deposition, Capillary
Flow, Dynamic Droplet Phase, Aggregation Phase, and Dried Morphology.
