Student groups construct simple conductivity probes and then integrate them into two different circuits to test the probe behavior in solutions of varying conductivity (salt water, sugar water, distilled water, tap water). The activity culminates with student-designed experiments that utilize the constructed probes. The focus is to introduce students to the fabrication of the probe and expose them to two different ways to integrate the probe to obtain qualitative and quantitative measurements, while considering the application and utility of a conductivity probe within an engineering context. A provided handout guides teams through the process: background reading and questions; probe fabrication including soldering; probe testing and data gathering (including circuit creation on breadboard); probe connection to Arduino (including circuit creation and code entry) and a second round of testing and data gathering; design and conduct their own lab experiments that use the probes; online electrolyte/nonelectrolyte reading, short video, comprehension check and analysis questions.

To increase students' awareness of possible invisible pollutants in drinking water sources, students perform an exciting lab requiring them to think about how solutions and mixtures exist even in unsuspecting places such as ink. They use alcohol and chromatography paper to separate the components of black and colored marker ink. Students witness first-hand how components of a solution can be separated, even when those individual components are not visible in solution.

Students investigate the property dependence between concentrations and boiling point. In section 1, students first investigate the boiling point of various liquid solutions. In section 2, they analyze data collected by the entire class to generate two boiling point curves, one for salt solutions and one for sugar solutions. Finally, in section 3, students use the data they have analyzed to determine how to create a solution that has a particular boiling point and is a cost-effective design.

Brainstorming is a team creativity activity that helps generate a large number of potential solutions to a problem. In this activity, students participate in a group brainstorming activity to generate possible solutions to their engineering design challenge. Students learn brainstorming guidelines and practice within their teams to create a poster of ideas. The posters are used in a large group critiquing activity that ultimately helps student teams create a design project outline. (Note: Conduct this activity in the context of a design project that students are working on; this activity is Step 3 in a series of six that guide students through the engineering design loop.)

Students quantify the percent of light reflected from solutions containing varying concentrations of red dye using LEGO© MINDSTORMS© NXT bricks and light sensors. They begin by analyzing a set of standard solutions with known concentrations of food coloring, and plot data to graphically determine the relationship between percent reflected light and dye concentration. Then they identify dye concentrations for two unknown solution samples based on how much light they reflect. Students gain an understanding of light scattering applications and how to determine properties of unknown samples based on a set of standard samples.

Students demonstrate the erythrocyte sedimentation rate test (ESR test) using a blood model composed of tomato juice, petroleum jelly and olive oil. They simulate different disease conditions, including rheumatoid arthritis, anemia, leukocytosis and sickle-cell anemia, by making appropriate variations in the particle as well as in the fluid matrix. Students measure the ESR for each sample blood model, correlate the ESR values with disease conditions and confirm that diseases alter blood composition and properties. During the activity, students learn that when non-coagulated blood is let to stand in a tube, the red blood cells separate and fall to the bottom of the tube, resulting in a sediment and a clear liquid called serum. The height in millimeters of the clear liquid on top of the sediment in a time period of one hour is taken as the sedimentation rate. If a disease is present, this ESR value deviates from the normal, disease-free value. Different diseases cause different ESR values because blood composition and properties, such as density and viscosity, are altered differently by different diseases. Thus, the ESR test serves as a real-world diagnostic screening test to identify indications of the presence of any diseases in people.

Students experiment with various ways to naturally dye materials using sources found in nature—roots, leaves, seeds, spices, etc.—as well as the method of extracting dyes. Then they analyze various materials using statistical methods and tackle an engineering design challenge—to find dyes that best suit the needs of a startup sustainable clothing company.

Students are introduced to the engineering design process within the context of reading Dr. Seuss’s book, Bartholomew and the Oobleck. To do so, students study a sample of aloe vera gel (representing the oobleck) in lab groups. After analyzing the substance, they use the engineering design process to develop and test other substances in order to make it easier for rain to wash away the oobleck. Students must work within a set of constraints outlined within the Seuss book and throughout the activity and use only substances available within the context of the plot. Students also take into consideration the financial and environmental costs associated with each substance.

To become familiar with the transfer of energy in the form of quantum, students perform flame tests, which is one way chemical engineers identify elements by observing the color emitted when placed in a flame. After calculating and then preparing specific molarity solutions of strontium chloride, copper II chloride and potassium chloride (good practice!), students observe the distinct colors each solution produces when placed in a flame, determine the visible light wavelength, and apply that data to identify the metal in a mystery solution. They also calculate the frequency of energy for the solutions.

Students gain an understanding of the difference between electrical conductors and insulators, and experience recognizing a conductor by its material properties. In a hands-on activity, students build a conductivity tester to determine whether different objects are conductors or insulators. In another activity, students use their understanding of electrical properties to choose appropriate materials to design and build their own basic circuit switch.

Students continue the research begun in the associated lesson as if they were biomedical engineers working for a pharmaceutical company. Groups each perform a simple chemical reaction (to precipitate solid calcium out of solution) to observe what may occur when Osteopontin levels drop in the body. With this additional research, students determine potential health complications that might arise from a new drug that could reduce inflammatory pain in many patients, improving their quality of life. The goal of this activity is to illustrate biomedical engineering as medical problem solving, as well as emphasize the importance of maintaining normal body chemistry.

In this activity, students investigate the properties of a heterogeneous mixture, trail mix, as if it were a contaminated soil sample near a construction site. This activity shows students that heterogeneous mixtures can be separated by physical means, and that when separated, all the parts will equal the whole.

This lesson plan introduces the properties of mixtures and solutions. A class demonstration gives the students the opportunity to compare and contrast the physical characteristics of a few simple mixtures and solutions. Students discuss the separation of mixtures and solutions back into their original components as well as different engineering applications of mixtures and solutions.

Through three lessons and their four associated activities, students are introduced to concepts related to mixtures and solutions. Students consider how mixtures and solutions and atoms and molecules can influence new technologies developed by engineers. To begin, students explore the fundamentals of atoms and their structures. The building blocks of matter (protons, electrons, neutrons) are covered in detail. The next lesson examines the properties of elements and the periodic table one method of organization for the elements. The concepts of physical and chemical properties are also reviewed. Finally, the last lesson introduces the properties of mixtures and solutions. A comparison of different mixtures and solutions, their properties and their separation qualities are explored.

Students conduct an experiment to determine how varying the composition of a construction material affects its strength. They make several adobe bricks with differing percentages of sand, soil, fibrous material and water. They test the bricks for strength by dropping them onto a concrete surface from progressively greater heights. Students graph the experiment results and use what they learn to design their own special mix that maximizes the bricks' strength. During the course of the experiment, students learn about variables (independent, dependent, control) and the steps of the engineering design process.

Students learn how to classify materials as mixtures, elements or compounds and identify the properties of each type. The concept of separation of mixtures is also introduced since nearly every element or compound is found naturally in an impure state such as a mixture of two or more substances, and it is common that chemical engineers use separation techniques to separate mixtures into their individual components. For example, the separation of crude oil into purified hydrocarbons such as natural gas, gasoline, diesel, jet fuel and/or lubricants.