UVA Sunlight Skin Sensor on Fingernail (image) Northwestern University Share Print E-Mail Caption This is a UVA sunlight skin sensor on fingernail. Credit Northwestern University Usage Restrictions Please credit Northwestern University. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.