The bumpers will tell the boe bot which way it needs to turn in order to get around obstacles or go through a maze.
Step 1: Time to Strip
Cut some strips of cardboard, enough, when stuck together, to hold the bumpers far enough out that the front wheel will not interfere. Glue the strips face to face and to the front of the boe bot.
Step 2: Make the Bumpers
Cut two strips of cardboard. Fold the strips in half (hamburger style). Poke holes through the centres of each half of the two strips. Stick one wire through each of the holes and coil the ends so the surface of contact is larger. Make sure the wires poke through on the side of the bumpers that folds in on itself. Cut out four small pieces of tin foil (just smaller than each half of the cardboard strips) and staple them onto the coiled wire.
Step 3: Attach the Bumpers to the Bot
Glue the backs of the bumpers onto the strips of cardboard that are already glued onto the boe bot. Connect the other ends of the wires into the mini-breadboard on the boe bot.