On the Formation of Regular Patterns from Drying Droplets and Their Potential Use for Bio-Medical Applications

When droplets containing suspensions evaporate and dryout, they leave patterns which are the result of the composition of the liquid as well as the dynamics of evaporation. Exploiting these patterns for technological applications and biomedical purposes could represent a real opportunity. Patterning technologies could indeed exploit the phenomenon for a quick, simple and inexpensive technique for depositing nanolayers. For biomedical applications, the use of patterns formed from drying biological fluids as a means of disease diagnosis is an attractive idea. Indeed by studying, understanding and interpreting pattern formation from evaporating droplets this idea could lead to a simple and rapid technique for screening of various life threatening diseases. We present a review on this topic and point to the challenges that still to be overcome if this idea is to be fully exploited. In addition we present the results of an experimental investigation, presenting patterns formed by nanoparticles from evaporating droplets in different conditions.