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.

This lesson introduces the concepts of longitudinal and transverse waves. Students see several demonstrations of waves and characterize them by transverse and longitudinal behavior. This lesson also introduces the Sunken Treasure theme of the Sound and Light unit a continuous story line throughout the lessons.

This unit focuses on teaching students about the many aspects of biomedical engineering (BME). Students come to see that BME is a broad field that relies on concepts from many engineering disciplines. They also begin to understand some of the special considerations that must be made when dealing with the human body. Activities and class discussions encourage students to think as engineers to come up with their own solutions to some of medical challenges that have been solved throughout the history of BME. Class time iincludes brainstorming and presenting ideas to the class for discussion. Specific activities include examination of the material properties and functions of surgical instruments and prosthetics, a simulation of the training experience of a surgical resident, and an investigation of the properties of fluid flow in vascular tissue.

Students act as surgical residents for the day. Working in teams, they use surgical instruments to complete tasks that are inside of a box, hidden from direct view. They are able to see inside of the box with the help of a "laparoscope" (webcam and flashlight). This engaging activity shows students one application of engineered medical instrumentation and gives them first-hand experience in seeing how form fits function. They also learn that an engineer's job does not end with a finished product because s/he must train others to use the device correctly.

Students engineer and evolve digital organisms with the challenge to produce organisms with the highest fitness values in a particular environment. They do this through use of the free Avida-ED digital evolution software application. The resulting organisms compete against each other in the same environment and students learn the benefits of applying the principles of natural selection to solve engineering design problems.

Students use a table-top-sized tsunami generator to observe the formation and devastation of a tsunami. They see how a tsunami moves across the ocean and what happens when it reaches the continental shelf. Students make villages of model houses and buildings to test how different material types are impacted by the huge waves. They further discuss how engineers design buildings to survive tsunamis. Much of this activity setup is the same as for the Mini-Landscape activity in Lesson 4 of the Natural Disasters unit.

Using a household fan, cardboard box and paper towels, student teams design and build their own evaporative cooler prototype devices. They learn about the process that cools water during the evaporation of water. They make calculations to determine a room's cooling load, and thus determine the swamp cooler size. This activity adds to students' understanding of the behind-the-scenes mechanical devices that condition and move air within homes and buildings for human health and comfort.

Playing the role of engineers in collaborations with the marketing and production teams in a chocolate factory, students design a container for a jumbo chocolate bar. The projects constraints mean the container has to be a regular trapezoidal prism. The design has to optimize the material used to construct the container; that is, students have to find the dimensions of the container with the maximum volume possible. After students come up with their design, teams present a final version of the product that includes creative branding and presentation. The problem-solving portion of this project requires students to find a mathematical process to express the multiple variables in the prism’s volume formula as a single variable cubic polynomial function. Students then use technology to determine the value for which this function has a maximum and, with this value, find the prism’s optimal dimensions.