Experiment with a haptic (touch) feedback interface by building your own "tactor" (tactile stimulator). Although commercial tactors cost hundreds of dollars, this one (Fig. 1) can be built for under ten dollars.
Submitted by Ace Monster Toys for the Instructables Sponsorship Program.
Step 1: Make Holes in the Speaker Cone
Since we are making a tactor, we want the voice coil to move as freely as possible, and make as little noise as possible. The answer is to perforate the loudspeaker cone (see Fig. 2). This can be done using the fine tip of a soldering iron, or the tip of a small brass rod heated in a flame. Do NOT use a screwdriver or any magnetic material, since there is a strong magnetic field around the voice coil. Disregarding this advice leads to the sort of results shown in Fig. 3.
Step 2: Make the Stimulator Tip
Make the stimulator tip (the part that contacts your skin). This should be made of a lightweight, non-magnetic material and should be about 3/16" in diameter, 3/16" long, rounded at the tip, and wide and flat at the base (where it will attach to the voice coil). Suitable materials could be the sawed-off tips of a light-emitting diode, small wire nut or push pin. In a pinch you could cut a suitable cylinder of wood by cutting a toothpick or wooden matchstick. Be sure to sand as necessary so the base is flat and the top is smooth and rounded. Using plastic or other non-magnetic tweezers, glue the stimulator tip to the speaker's voice coil with a small drop of Super Glue. Fig. 4 shows the finished tip made from the sawed-off end of a small wire nut.
Step 3: Make the Cover
Drill a hole in the dead center of the film can top that is large enough to clear the stimulator tip, and smooth the edges of the hole with a small, round file. The film can cover should now slip snugly onto the loudspeaker, with the stimulator tip peeking out of the center hole.