Light weight sensor

Hello everyone i am new on this forum, i am making a project where i need to measure something like 10 to 25 grams and then on or off the circuit accordance to weight.
Is there any light weight sensor available for arduino which is small is size, cheap, and can measure these quantities with somewhat accuracy.
Thank you in advance and sorry for my bad English.

maybe try to write "digital scale arduino" in ebay, i hope it helps