Designer Yuko Taguchi has created this ingenious wind-up lamp:
“This is for people who can’t sleep without the light. Also, people who read in the bed sometimes forget to turn off the light. The key functions as a switch and a timer. Wind-up to turn the light on before you go to bed. The light will stay on until the key winds back. You will come to know how many times you need to wind-up. Its main source of power comes from its powerful spring-driven generator. As the high carbon tensile steel spring unwinds, power is transferred to a small dynamo electric generator which produces enough electricity to power of the light.”
Not only does this save electricity by turning off the light after you’ve fallen asleep, you don’t even have to plug it in.