Semi-conducting elements previously mentined such as some types of silicium and carbon structures are used to produce many elements starting with resistors. A resistor plugged along a cricuit will enble to decrease (and adapt) the flow of electrons between the power source and the actuator.  We can say it opposes a resistance to the current.

Infact, every elements (enven wires) of an electronic circuit oppose a resistance to a current, and for any element submitted to a Voltage, the same equation links the Voltage, the resistance of the element and the current (I) crossing the Element:

U = R * I

 with U in Volts, R in Ohms and In Amps

At Papier Logik, we produce our own resistors (and other elements such as sensors ) using semi-conducting paper. For a given voltage, we know how to produce elements with the good resistance value so that we control the current in a circuit.