Let's Make Robots!

Tactile sensor

touch sensor
  • Target environment:

I planned to use tactile sensor on my arduino based robot. In the end I used IR sensors instead. anyway, there are applications where tactile sensor is the right choice.

There are basically two options:
1. use some microswitch and add some antenna to it
2. create antenna that acts as a switch as well - this is the case

I got slightly inspired by the antennas in the Boe-Bot kit, but I had to face one issue - my chassis is made of plastics, thus I can not use it as a ground for electronics parts. There was need to create another metal part (not connected with antenna if there is no object in front of it) that would act as simple switch.

What I used:
- steel wire (you can get that at most hobby shops) - thinner means more sensitive sensor
- piece of universal printed circuit (or any printed circuit, if you create your own for your bot
- some mean of attaching the sensor to robot, in my case it was little screw (number 1,5 or 2 in metric)

What to do:
- you have to decide what should be the suitable shape and dimension of the antenna
- start shaping antenna from the tip that is away from robot, you will be finishing with the part that is being soldered to the printed circuit
- leave some straight part on the antenna near the end that is being soldered to the circuit board
- bend the other wire so that it has small grommet on the end - this will act as the other part of the "switch" - you can see it on the bottom image
- solder both wires to the circuit board so that the antenna goes through the grommet on the shorter piece of wire, make sure, they are not soldered to the same condictive part of the circuit board. HINT: if you add some right-angle bend on the end that is being soldered, you can gain a lot of strenght and the sensor will last longer
- add the mean of attaching the sensor, e.g. screw
- depending on the sort of wire you use, there may be some corrosion over the time (as you can see on my pictures) probably caused by the fact, that i scratched the wire while bending it. you can precede this by cleaning the wire and adding some solder on the parts of the wires that touch each other