I worked in the Engineering Department at Drexel University for Dr. Ying Sun. I have 2 mentors: Dr. Abhijit Joshi (PhD in mechanical engineering) and Viral Chhasatia (PhD candidate).
The major focus on the lab is the effects of humidity on contact angles of a water drop.
You are always rushing out of the door in the morning (well, I am anyway). You accidentally let coffee drip on the table and of course have no time to wipe it up. After work, you come home, sit down at the table looking down in thought and see that drop. Well, not a drop but the stain it left. And you begin to wonder why and how that stain got there before you wipe it up. You begin to wonder about the evaporation process of the drop. You wonder if all drops of liquid leave a stain....You wonder if the ring-like stain has a specific circumference and why if so......You wonder what happens to drops on different surfaces, drops on surfaces that are clean or treated....YOU BECOME CONSUMED WITH DROPS OF LIQUIDS ON SURFACES!!!!!!!
I have had the honor to help Dr. Ying Sun and her team by measuring the contact angles of drops that have different humidities. The coffee stain is just one of the drops that have been studied. Drops of water, inkjet, and other liquids have also been analyzed. There is something special about WHY humidities interact with the contact angle of drops. And, the solution is closer than you can imagine!!!!!