A robot that attempts to light a match!
The circuit is a Miller Solar Engine, employing a single 65mm solar panel, a TC54 voltage detector and 4700 uF and 10 uF capacitors to periodically fire a low-voltage motor and grind a match head on a striker held against it by a spring.
Total storage capacitance is 4700 uF; at the 3.16V triggering voltage of the circuit, the system is storing and then releasing 0.0235 joules of energy. The timing capacitor across the voltage detector has a capacitance of 10 uF.
(NB: out of an abundance of caution, we’re replacing the real match with a dummy match if/when our robot is put on display)