Find out how chemists are speeding up swimmers with high-tech new swimwear. The final episode in our four part celebration of National Chemistry Week.

Intro theme and various sound effects by Adam Dylewski; music by Kevin MacLeod (incompetech.com); Creative Commons licensed audio from freesound.iua.upf.edu and SoundSnap.com include sounds by SFX Bible, Fred Weinberg, Shriek Productions, man, FranciscoPadilla and Radio Mall.