How Does a Touch Sensor Work?
Our hands use the sense of touch to inform us of our surroundings. Do you think engineers have been able to replicate the sense of touch in robots?Copyright Barrett Technology Inc. via NASA http://spinoff.nasa.gov/Spinoff2008/hm_1.html
Students learn about how touch sensors work, while reinforcing their similarities to the human sense of touch. They look at human senses and their electronic imitators, with special focus on the nervous system, skin and touch sensors. A PowerPoint® presentation explains stimulus-to-response pathways, how touch sensors are made and work, and then gives students a chance to handle and get familiar with the LEGO touch sensor, including programming LEGO® MINDSTORMS® EV3 robots to use touch sensor input to play music. Students take pre/post quizzes and watch a short online video. The mini-activities prepare students for the associated activity. This lesson and its associated activity enables students to appreciate how robots can take input from sensors, and use that to make decisions to move.
Touch sensors—called tactile sensors by engineers—are part of many devices that we use every day. Tactile sensors are sensitive to touch, force or pressure, and are made using light (optical), electricity or magnetism. The stimulus-to-response pathways seen in electronic touch sensor operation mimics the human body process that involves our skin, signal transmission via the nervous system, and brain. For instance, computer keys are touch sensors that inform the computer which keys are being pressed. All keypads have touch sensors. Similarly, you can open a car door using a touch sensor that generates an infrared signal that goes to the car's computer informing it to unlock the door. Touchscreens on phones and computer tablets enable even more exquisite communication between people and machines. The use of sensors has exploded into the design of uncountable every day tools, equipment, appliances and devices.
After this lesson, students should be able to:
- Describe how touch sensors work.
- Compare the touch sensor to the human sense of touch.
- Program a LEGO MINDSTORMS EV3 robot with a touch sensor.
- Provide a basic explanation of how sensors are integrated into robots via careful programming.