Image: Annie Cavanagh and David McCarthy

To paraphrase Ben Franklin, coffee is proof that God loves us and wants us to work. The beautiful image above is a false-colored scanning electron micrograph of the crystals of caffeine, the magical thing that makes coffee work:

Caffeine is a bitter, crystalline xanthine alkaloid that acts as a stimulant drug. In plants, caffeine functions as a defence mechanism. Found in varying quantities in the seeds, leaves and fruit of some plants, caffeine acts as a natural pesticide that paralyses and kills certain insects feeding on the plant. The main crystals of caffeine were 400-500 microns long; however, this crystal group formed on the end of the larger crystal and measures around 40 microns in length.

It's part of the winners' gallery over at Wellcome Image Awards 2012: Link