Rocks cover the earth's surface, including what is below or near human-made structures. With rocks everywhere, breaking rocks can be hazardous and potentially disastrous to people. Students are introduced to three types of material stress related to rocks: compressional, torsional and shear. They learn about rock types (sedimentary, igneous and metamorphic), and about the occurrence of stresses and weathering in nature, including physical, chemical and biological weathering.

Students explore whether rooftop gardens are a viable option for combating the urban heat island effect. Can rooftop gardens reduce the temperature inside and outside houses? Teams each design and construct two model buildings using foam core board, one with a "green roof" and the other with a black tar paper roof. They measure and graph the ambient and inside building temperatures while under heat lamps and fans. Then students analyze the data and determine whether the rooftop gardens are beneficial to the inhabitants.

Students learn about five types of renewable energy that are part of engineering solutions to help people in rural communities use less and cleaner energy for cooking and heating. Specifically, students learn about the pollution and health challenges facing families in rural China, and they are introduced to the concept of optimization. Through an energy game, students differentiate between renewable and non-renewable sources of energy.

Students build a saltwater circuit, which is an electrical circuit that uses saltwater as part of the circuit. Students investigate the conductivity of saltwater, and develop an understanding of how the amount of salt in a solution impacts how much electrical current flows through the circuit. They learn about one real-world application of a saltwater circuit — as a desalination plant tool to test for the removal of salt from ocean water.

Student teams practice water quality analysis through turbidity measurement and coliform bacteria counts. They use information about water treatment processes to design prototype small-scale water treatment systems and test the influent (incoming) and effluent (outgoing) water to assess how well their prototypes produce safe water to prevent water-borne illnesses.

Students use their knowledge about how healthy heart valves function to design, construct and implant prototype replacement mitral valves for hypothetical patients' hearts. Building on what they learned in the associated lesson about artificial heart valves, combined with the testing and scoring of their prototype heart valve designs in this activity, students discover the pros and cons of different types of artificial heart valves based on materials, surgery requirements, and lifespan.

Students learn how different characteristics of shapes—side lengths, perimeter and area—change when the shapes are scaled, either enlarged or reduced. Student pairs conduct a “scaling investigation” to measure and calculate shape dimensions (rectangle, quarter circle, triangle; lengths, perimeters, areas) from a bedroom floorplan provided at three scales. They analyze their data to notice the mathematical relationships that hold true during the scaling process. They see how this can be useful in real-world situations like when engineers design wearable or implantable biosensors. This prepares students for the associated activity in which they use this knowledge to help them reduce or enlarge their drawings as part of the process of designing their own wearables products. Pre/post-activity quizzes, a worksheet and wrap-up concepts handout are provided.

Students learn about the types of seismic waves produced by earthquakes and how they move the Earth. The dangers of earthquakes are presented as well as the necessity for engineers to design structures for earthquake-prone areas that are able to withstand the forces of seismic waves. Students learn how engineers build shake tables that simulate the ground motions of the Earth caused by seismic waves in order to test the seismic performance of buildings.

This unit describes a general approach to guiding students to complete service-based engineering design projects, with specific examples provided in detail as associated activities. With your class, brainstorm ideas for engineering designs that benefit your community or a specific person in your community. Then, guided by the steps of the engineering design process, have students research to understand background science and math, meet their client to understand the problem, and create, test and improve prototype devices. Note that service-based projects often take more time to prepare, especially if you arrange for a real client. However, the authors notice that students of both genders and all ethnicities tend to respond with more enthusiasm and interest to altruistic projects.

Students learn about how engineers design and build shake tables to test the ability of buildings to withstand the various types of seismic waves generated by earthquakes. Just like engineers, students design and build shake tables to test their own model buildings made of toothpicks and mini marshmallows. Once students are satisfied with the performance of their buildings, they put them through a one-minute simulated earthquake challenge.

Students investigate the critical nature of foundations as they learn differences between shallow and deep foundations, including the concepts of bearing pressure and settlement. Using models representing a shallow foundation and a deep pile foundation, they test, see and feel the effects in a cardboard box test bed composed of layers of pebbles, soil and sand. They also make bearing pressure calculations and recommendations for which type of foundations to use in various engineering scenarios.

Students use their understanding of projectile physics and fluid dynamics to find the water pressure in water guns. By measuring the range of the water jets, they are able to calculate the theoretical pressure. Students create graphs to analyze how the predicted pressure relates to the number of times they pump the water gun before shooting.

Students learn about the major factors that comprise the design and construction cost of a modern bridge. Before a bridge design is completed, engineers provide overall cost estimates for construction of the bridge. Students learn about the components that go into estimating the total cost, including expenses for site investigation, design, materials, equipment, labor and construction oversight, as well as the trade-off between a design and its cost.

Students explore building a pyramid, learning about the simple machine called an inclined plane. They also learn about another simple machine, the screw, and how it is used as a lifting or fastening device. During a hands-on activity, students see how the angle of inclination and pull force can make it easier (or harder) to pull an object up an inclined plane.

Students learn about two types of friction static and kinetic and the equation that governs them. They also measure the coefficient of static friction experimentally.

Students develop a persuasive peer-to-peer case against smoking, with the goal to understand how language usage can influence perception, attitudes and behavior.

Students learn about one method used in environmental site assessments. They practice soil sampling by creating soil cores, studying soil profiles and characterizing soil profiles in borehole logs. They use their analysis to make predictions about what is going on in the soil and what it might mean to an engineer developing the area.

Students learn the basics about soil, including its formation, characteristics and importance. They are also introduced to soil profiles and how engineers conduct site investigations to learn about soil quality for development, contamination transport, and assessing the general environmental health of an area.

Students are introduced to the sound environment as an important aspect of a room or building. Several examples of acoustical engineering design for varied environments are presented. Students learn the connections between the science of sound waves and engineering design for sound environments.

Students follow the steps of the engineering design process to create their own ear trumpet devices (used before modern-day hearing aids), including testing them with a set of reproducible sounds. They learn to recognize different pitches, and see how engineers must test designs and materials to achieve the best amplifying properties.