How can you use a sharpie to make a circuit board?

You can use a Sharpie to create a simple circuit board by drawing the circuit paths directly onto a copper-clad board. First, clean the copper surface, then use the Sharpie to trace the desired circuit layout, ensuring the lines are thick enough to conduct electricity. After the drawing is complete, you can etch away the unmarked copper using a suitable etching solution, leaving only the traced paths. Finally, rinse off the etching solution, and you can solder components onto the remaining copper traces to complete the circuit.