I create this simple Iron man heart using some cardboard and a cardboard tube!!!
Few leds and two 1.5 volts battery!
I cut the cardboard circle regarding the tube size and then I cut the circle and the shape to looks like Iron man heart shape.
For the electric circuit nothing fancy just one switch on/off attached on the tube.
You can turn the front circle in order to see or not led.
In the dark, the effect is pretty nice!!!!