Molecules and Organisms

It is almost instinctive when you first get the PocketLab Air to breathe directly on it just to see what happens. As seen below, of the PocketLab Air's seven sensors, five of them detect changes from a direct human breath. These parameters are carbon dioxide, particulate matter, temperature, humidity, and pressure. The most interesting of these is the sharp rise in carbon dioxide which, as the most important greenhouse gas, brings about strong connections to the topic of climate change.

Background Information about Ozone

Ozone (O3) in our atmosphere is both good and bad. There is a helpful saying to remember is, “Ozone: good up high, bad nearby.” The “good” ozone is ozone high in our atmosphere that is part of the ozone layer. The ozone layer protects us from the sun’s ultraviolet rays. “Bad” ozone is ozone that occurs at ground level, where it can be inhaled. Ground level ozone is a pollutant and creates smog. 

Background Information on Particulate Matter

Particulate matter consists of small particles suspended in the atmosphere. Dust, pollen, sea salt, soil particles, mold, soot, smoke, and other fine substances create a mixture of particulate matter that we inhale with every breath. According to the EPA, particulate matter greater than 10 micrometers is generally filtered away in our nose and throat. Particulates less than 10 micrometers can often pass into the lungs.

Background Information

Carbon dioxide circulates naturally in Earth’s atmosphere as part of the carbon cycle (the process in which carbon dioxide is exchanged between the atmosphere, oceans, soil, plants, and animals). According to the EPA, since the industrial revolution, humans have altered the carbon cycle through activities like burning fossil fuels, which adds CO2 to the cycle, and deforestation which reduces natural ways in which CO2 is removed. 

Brownian Motion

Brownian motion can be defined as the random motion of particles in a liquid or gas caused by the bombardment from molecules in the containing medium.  Have you ever looked at dust particles in the sunlight shining through a window?  They appear to move about randomly, even defying gravity.  This is an example of Brownian motion in which the dust particles are bombarded on all sides by gas molecules in the air.  Other examples of Brownian motion include the motion of grains of pollen on the surface of still water, the dif

A PocketLab Voyager Hand Dynamometer

Hand and finger strength is vital in many aspects of life--from sports such as rock climbing to jobs including airline baggage workers.  PocketLab Voyager's tactile sensor can be used to construct a very simple hand dynamometer to measure strength of a person's hands and fingers.  Figure 1 shows a simple dynamometer constructed by the author.  It consists of a 2" x 2" x 4" block of wood to which the PocketLab tactile sensor has been attached using removable double stick poster tape.

Heel Pressure

Do you really know how to walk or run?  PocketLab's tactile pressure sensor provides for an opportunity for your students to investigate foot pressure during these activities.  Improper form can ultimately lead to unwanted visits to a podiatrist.  Whenever you take a step, your body places pressure on muscles, joints and tendons in your legs, knees, ankles, feet and toes.   Controlling heel pressure is a key factor to prevent injuries in this regard.

Introduction to Tactile Pressure

Tactile pressure sensors are used for a wide variety applications including, but not limited to the following:

The eye is one of the many marvels of the human body.  The colored iris of the eye, surrounding the pupil, acts as a diaphragm to keep the amount of light entering the eye fairly constant.  If you walk out the door of your house to a sunny yard, the iris opening gets smaller letting less light into your eye.  If you enter a dark room after watching your favorite television program, the iris gets larger to allow more light to enter your eye.  This is a protective reflex, as too much light could damage the retina, which is where the image forms in the eye, similar to the film of a traditional