In this lesson the students will learn how the heart functions. Students will be introduced to the concept of action potential generation. The lesson will explain how action potential generation causes the electrical current that causes muscle contraction in the heart. Students will be introduced to the basic electrical signal generated by the heart; P, QRS, and T waves. The lesson will approach the heart from an engineering standpoint and encourage students to design ways to improve heart function. Students will also learn the basic steps of the engineering design process.

Students work together in small groups, while competing with other teams, to explore the engineering design process through a tower building challenge. They are given a set of design constraints and then conduct online research to learn basic tower-building concepts. During a two-day process and using only tape and plastic drinking straws, teams design and build the strongest possible structure. They refine their designs, incorporating information learned from testing and competing teams, to create stronger straw towers using fewer resources (fewer straws). They calculate strength-to-weight ratios to determine the winning design.

Music and sound are two different concepts that share much in common. Determining the difference between the two can sometimes be difficult due to the subjective nature of deciding what is or is not music. The goal of this activity is to take something constructed by students, that would be normally classified as just sound and have the class work together to make what can be perceived to be music. Students construct basic stringed instruments made of shoeboxes and rubber bands. This activity aims to increase student understanding of what distinguishes music from sound.

Through two lessons and their associated activities, students do the work of scientists by designing their own experiments to answer questions they generate. Through a simple activity involving surface tension, students learn what a hypothesis is—and isn't—and why generating a hypothesis is an important aspect of the scientific method. In the second activity, with bubble gum to capture their interest, students learn to design and conduct controlled experiments to answer their own questions about the amounts of sugar (or artificial sweetener) in bubble or chewing gum.

Students observe natural selection in action and investigate the underlying mechanism, including random mutation and differential fitness based on environmental characteristics. They do this through use of the free AVIDA-ED digital evolution software application.

Students culture cells in order to find out which type of surfactant (in this case, soap) is best at removing bacteria. Groups culture cells from unwashed hands and add regular bar soap, regular liquid soap, anti-bacterial soap, dishwasher soap, and hand sanitizer to the cultures. The cultures are allowed to grow for two days and then the students assess which type of soap design did the best job of removing bacteria cells from unwashed hands. Students extend their knowledge of engineering and surfactants for different environmental applications.

In this activity, students act as environmental engineers involved with the clean up of a toxic spill. Using bioremediation as the process, students select which bacteria they will use to eat up the pollutant spilled. Students learn how engineers use bioremediation to make organism degrade harmful chemicals. Engineers must make sure bacteria have everything they need to live and degrade contaminants for bioremediation to happen. Students learn about the needs of living things by setting up an experiment with yeast. The scientific method is reinforced as students must design the experiment themselves making sure they include a control and complete parts of a formal lab report.

Students learn about providing healthcare in a global setting and the importance of wearing protective equipment when treating patients with infectious diseases like Ebola. They learn about biohazard suits, heat transfer through conduction and convection and the engineering design cycle. Student teams design, create and test (and improve) their own Ebola biohazard suit prototypes that cover one arm and hand, including a ventilation system to cool the inside of the suit.

Students are introduced to static equilibrium by learning how forces and torques are balanced in a well-designed engineering structure. A tower crane is presented as a simplified two-dimensional case. Using Popsicle sticks and hot glue, student teams design, build and test a simple tower crane model according to these principles, ending with a team competition.

Students apply their knowledge of constructing and programming LEGO MINDSTORMS (TM)NXT robots to create sumobots - strong robots capable of pushing other robots out of a ring. To meet the challenge, groups follow the steps of the engineering design process and consider robot structure, weight and gear ratios in their designs to make their robots push as hard as possible to force robot opponents out of the ring. A class competition serves as the final test to determine the best designed robot, illustrating the interrelationships between designing, building and programming. This activity gives students the opportunity to be creative as well as have fun applying and combining what they have learned through the previous activities and lessons in this and prior units in the series. A PowerPoint (tm) presentation, pre/post quizzes and a worksheet are provided.

Students are challenged to design, build and test small-scale launchers while they learn and follow the steps of the engineering design process. For the challenge, the "slingers" must be able to aim and launch Ping-Pong balls 20 feet into a goal using ordinary building materials such as tape, string, plastic spoons, film canisters, plastic cups, rubber bands and paper clips. Students first learn about defining the problem and why each step of the process is important. Teams develop solutions and determine which is the best based on design requirements. After making drawings, constructing and testing prototypes, they evaluate the results and make recommendations for potential second-generation prototypes.

Use this hands-on activity to demonstrate rotational inertia, rotational speed, angular momentum, and velocity. Students build at least two simple spinners to conduct experiments with different mass distributions and shapes, as they strive to design and build the spinner that spins the longest.

Students are introduced to superhydrophobic surfaces and the "lotus effect." Water spilled on a superhydrophobic surface does not wet the surface, but simply rolls off. Additionally, as water moves across the superhydrophobic surface, it picks up and carries away any foreign material, such as dust or dirt. Students learn how plants create and use superhydrophobic surfaces in nature and how engineers have created human-made products that mimic the properties of these natural surfaces. They also learn about the tendency of all superhydrophobic surfaces to develop water droplets that do not roll off the surface but become "pinned" under certain conditions, such as water droplets formed from condensation. They see how the introduction of mechanical energy can "unpin" these water droplets and restore the desirable properties of the superhydrophobic surface.

At this stage of the "Lost in the Amazon" (hypothetical) adventure, students determine what supplies they will take with them to survive their trip through the Amazon. They use estimation and basic math skills to determine how much they can carry and what they can use to survive in the jungle environment as they travel on to their destination.

Surface tension accounts for many of the interesting properties we associate with water. By learning about surface tension and adhesive forces, students learn why liquid jets of water break into droplets rather than staying in a continuous stream. Through hands-on activities, students learn how the combination of adhesive forces and cohesive forces cause capillary motion. They study different effects of capillary motion and use capillary motion to measure surface tension. Students explore the phenomena of wetting and hydrophobic and hydrophilic surfaces and see how water's behavior changes when a surface is treated with different coatings. A lotus leaf is a natural example of a superhydrophobic surface, with its water-repellent, self-cleaning characteristics. Students examine the lotus effect on natural leaves and human-made superhydrophobic surfaces, and explore how the lotus leaf repels dewy water through vibration. See the Unit Overview section for details on each lesson in this unit.

Students are presented with the question: "Why does a liquid jet break up into droplets?" and introduced to its importance in inkjet printers. A discussion of cohesive forces and surface tension is included, as well as surface acting agents (surfactants) and their ability to weaken the surface tension of water. Students observe the effects of surface tension using common household materials. Finally, students return to the original question through a homework assignment that helps them relate surface tension and surface area to the creation of water droplets from a liquid jet.

Students extend their understanding of surface tension by exploring the real-world engineering problem of deciding what makes a "good" soap bubble. Student teams first measure this property, and then use this measurement to determine the best soap solution for making bubbles. They experiment with additives to their best soap and water "recipes" to increase the strength or longevity of the bubbles. In a math homework, students perform calculations that explain why soap bubbles form spheres.

In an activity that integrates science and art, students see, experience and harness the phenomenon of surface tension as they create beautiful works of art. Students conduct two experiments related to surface tension floating objects on the surface of water and creating original artwork using floating inks. They also learn historical and cultural information through an introduction to the ancient Japanese art form of suminagashi. They take the topic a step further by discussing how an understanding of surface tension can be applied to solve real-world engineering problems and create useful inventions.

Students learn about the basics of molecules and how they interact with each other. They learn about the idea of polar and non-polar molecules and how they act with other fluids and surfaces. Students acquire a conceptual understanding of surfactant molecules and how they work on a molecular level. They also learn of the importance of surfactants, such as soaps, and their use in everyday life. Through associated activities, students explore how surfactant molecules are able to bring together two substances that typically do not mix, such as oil and water. This lesson and its associated activities are easily scalable for grades 3-12.