Lesson How Do Human Sensors Work?

Learning Objectives

After this lesson, students should be able to:

• Describe how the five human senses work.
• Compare the human senses to the electronic sensors in a robot.
• Program the robot with sensors to navigate a maze and compare that to a human walking by following instructions.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Worksheets and Attachments

Pre-Req Knowledge

Students should have completed the first lesson in the unit, What Is a Robot?, which introduces them to the EV3 robot and the basics of its programming.

Introduction/Motivation

Use the How Do Human Sensors Work? Presentation (a PowerPoint file) to present students with the lesson content. Use the Lesson Background information to guide your presentation of the concepts, slide-by-slide.

Start the lesson with an introduction to the human senses and how they work: eyes, ears, skin, nose and touch. Then, introduce robot sensors and how they work.

Sum it all up by conducting the Movement Task Using Sensors-Humans and Robots associated activity to implement the concept of how humans use their five senses to perform a certain task compared to how a robot uses its sensors to do the same task.

Lesson Background and Concepts for Teachers

Taste Activity Materials List

For the taste activity (slide 9):

• candy with similar texture, in multiple flavors, such as Starburst or Skittles
• paper towels

How do human sensors work? (presentation)

Use the How Do Human Sensors Work? Presentation to teach the lesson concepts, along with the suggested slide-by-slide guidance below. Another PowerPoint file, Understanding How We Use Sensors vs. How a Robot Uses Sensors Presentation is provided for the activity. The worksheets and pre-/post-assessment sheets are slides in the lesson PowerPoint file, as well as attached PDF files. Use the Human and Robot Sensors Assessment PowerPoint file to play the fun Jeopardy game activity as a post-lesson assessment.

• (Before slide 3) Hand out the pre-assessment sheets and give students time to answer the three questions. Answers are provided on slide 3.
• Inform the students that this lesson is about the five human senses and how they work, and then about comparing them with similar sensors in robots.
• (Slides 4-5) Describe what is meant by a sensor. A type I example sensor is one used on an automatic door that detects the presence of a person or object. It does not detect how many people are present, just whether or not something is there, in order to determine whether or not to open the door. A type II example sensor is a scale that tells exactly how much a person weighs or a car's speedometer that determines exactly how fast a car is moving. A garage door sensor usually a sensor that sends an infrared beam across the garage opening; one side is a transmitter and one is a receiver. If the beam is broken, the door is not permitted to close, as a safety feature.
• (Slides 6-7) Provide an overview of human sensors and what they do.
• (Slide 8) Introduce the sense of touch and human touch sensors.
• (Before slide 9) Ask: What location in your arm is most sensitive to touch and why? Write student responses on the classroom board, without giving them any help. Then, do the activity described in slide 9 so that students can answer the question themselves. After the activity, repeat the question and discuss it as a class. Explain that the particular area in their arms is more sensitive because it has more nerve endings.
• (Before slides 10-12) Ask: How do your eyes works as a sensor? Again, write student responses on the board, without giving them any help. Expect them to be able to get the idea of a sensing element, and then the transmission of the signal to the brain. Then explain the components of the eye using slides 10-12. Hand out copies of slide 13 and ask students to label the parts of the eye on the worksheet.
• (Slides 14-16) Explain the ear sensor in a similar way.
• (Slide 17) Describe how the human nose works. Play the How Smell Works video to explain how dogs can smell much better than humans.
• (Slides 18-19) Explain the sense of taste, followed by an interesting five-minute activity described on slide 19. Be prepared with a supply of candy that has similar texture in multiple flavors, such as Starburst or Skittles.
• Summarize the human senses and how they work.
• (Before slides 20-23) Ask: How many human senses do you think have been duplicated in robots? Explain all about robot sensors and how they work. The answer to the question at the bottom of slide 23 is: Certain animals like bats and dolphins have senses that are similar to ultrasonic sensors; we call their ability to sense in this way a process called echolocation.
• (Slide 24) Summarize the comparison of human and robot sensors.
• Next, conduct the associated activity.
• (Slides 25-26) After the associated activity is done, administer post-assessment questions, with answers on slide 26.

Supplementary Background Material

It is helpful to have photographs and schematic diagrams to show students how each of the five senses works, and then do the same for the engineering/robotic counterparts.

1. How do our eyes work?

https://www.aoa.org/news/inside-optometry/infantsee-program-heartens-aspiring-ods

http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1730

https://www.answers.com/Q/How_is_a_camera_like_a_human_eye&altQ=Compare_the_parts_of_a_camera_to_the_human_eye

• Light is refracted or made to change directions by the cornea, the outermost part of the eye.
• This light is directed through the pupil, which is a hole through which it can pass. The surrounding muscular tissue contained in the iris (the colored part of the eye) controls the pupil size.
• The light that enters the back of the eye through the pupil is redirected by the eye's lens, which directs the light to nerves in the back of the eye that convert light into electrical signals. Two main types of such nerves are cones, which are concentrated in the middle of the eye, detect details and colors in good light., and rods, which are concentrated in the sides of the eye, and detect the presence of objects in low light.
• Cones and rods send electrical signals through the optic nerve to the brain.

2. How do our ears work?

http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1463

• Sounds that you hear are made of sound waves, which are disturbances in the air that vibrate. These vibrations travel through the air, since vibrating air causes air next to it to vibrate.
• Sound waves enter your ear canal and cause your eardrum to vibrate.
• The vibration of your eardrum is passed on through three structures called the hammer, anvil and stirrup, to a fluid-filled structure called the cochlea.
• Different pitches of sound cause different parts of the cochlea to vibrate.
• When the fluid in the cochlea vibrates, it moves little hairs that connect to nerve cells and send electrical signals to the brain.

3. How do we feel using our skin?

https://www.medindia.net/know_ur_body/anatomy-of-skin.asp

• Your skin contains millions of highly sensitive nerve endings that are able to detect several different types of stimulation, including pressure, temperature and pain.
• When these specialized receptors are stimulated, they send signals through the nervous system to the brain, which interprets them.

4. How do we smell using our noses?

https://health.howstuffworks.com/mental-health/human-nature/perception/question139.htm

https://health.howstuffworks.com/mental-health/human-nature/perception/smell.htm

• Small particles of almost everything around us are present in the air. For example, when you open a pizza box, particles of the pizza enter the air around you, and enter your nose when you breathe in.
• These particles come into contact with a set of nerve endings in your upper nasal passage. These nerve endings send signals through other nerves to your brain, which is able to make sense of the smell.
• You are able to distinguish between hundreds of different smells, while dogs can distinguish thousands.

5. How do we taste using our tongues?

https://health.howstuffworks.com/mental-health/human-nature/perception/taste.htm

• Your tongue has several sensory receptors called taste buds that are able to detect one of five different flavors: sweet, salty, bitter, sour and umami.
• Umami is a flavor that is detected in many high-protein foods, such as meats, cheeses, tomatoes and mushrooms, and is generally described as being a savory, meaty taste.
• These receptors are comprised of cells called gustatory receptor cells. These cells have hairs that detect taste from the food that you eat. Then these cells send information through the nervous system to the brain, which detects the information as taste.
• Flavor is much more than just taste. It comprises taste, smell, texture of food and even other sensations such as pain when you eat something spicy. Eating food with your nose blocked shows a marked decrease in flavor, even though the taste is the same.

Human body systems: http://ssec.si.edu/stc-program-human-body-systems-unit-kit

Parts of the brain: http://serendip.brynmawr.edu/bb/kinser/Structure1.html

Associated Activities

• Movement Task Using Sensors - Humans and Robots - Students explore how sensors are used to perform a movement task, using human and robot examples.

Lesson Closure

To test students' understanding, play the How do Human Sensors Work? Jeopardy game during the last 10 minutes.

Review the sensors in the human body and the corresponding robot sensors.

Ask students which body sensors are similar to the following LEGO robot sensors:

• Ultrasonic and color sensors: These are like our eyes.
• Touch sensors: These provide robots with a sense of touch, somewhat like our hands and feet.

We use our senses to make decisions about movement and actions in much the same manner as a robot uses its sensors to make decision and corresponding actions. Engineers are always trying to develop sensors to be more like the senses in our bodies. Additional robotic sensors measure temperature and pressure, similar to what we sense via our skin. Engineers often get ideas for the design of sensors and robots from the amazing capabilities of the human body and brain, and the result is that they have a lot of similarities. So, the human is in some sense similar to a robot! (This was the topic of lesson 3 of the unit.)

Assessment

Pre/Post Lesson Assessment

Before starting the lesson, administer the pre-/post-assessment worksheet (slide 2 in lesson PowerPoint) to help students begin thinking about human senses and their robotic parallels. Do not tell them the answers. Then, after the lesson, administer the same worksheet. Compare pre/post answers to assess their learning. Alternatively, just ask them if they would change any of their pre-lesson worksheet answers; ask them to explain which ones and why.

Jeopardy Game Post-Assessment

Allow 10 minutes for a fun post-lesson assessment in the form of a Jeopardy Assessment Game. The PowerPoint presentation is programmed to run the entire game starting on slide 2 so all you have to do is click on the boxes and keep score. The game provides the answer, and as usual in Jeopardy, students need to come up with the question.

Copyright

Contributors

Supporting Program

Acknowledgements

This curriculum was developed under National Science Foundation GK-12 grant no. DGE 0440524. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.