The concept behind this **Lie Detector Circuit** is that, we assume when a person lie he kind of pumps up his anxiety level which makes him sweat and develop moisture on his skin. We then use this piece of circuit to detect if there is moisture on his skin and based on the result we glow and LED, a green one for truth and red for lie. Of course yes this cannot be claimed as a lie detector, but you can use this to play with your friends and have fun. More than that you get to learn stuff