Students learn about population density within environments and ecosystems. They determine the density of a population and think about why population density and distribution information is useful to engineers for city planning and design as well as for resource allocation.

Using Avida-ED freeware, students control a few factors in an environment populated with digital organisms, and then compare how changing these factors affects population growth. They experiment by altering the environment size (similar to what is called carrying capacity, the maximum population size that an environment can normally sustain), the initial organism gestation rate, and the availability of resources. How systems function often depends on many different factors. By altering these factors one at a time, and observing the results, students are able to clearly see the effect of each one.

This lesson is the second of two that explore cellular respiration and population growth in yeasts. In the first lesson, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arose during the first lesson and its associated activity, in this lesson students work in small groups to design experiments that will determine how environmental factors affect yeast population growth.

Working in teams, students learn the basics of fluid power design using the PFPD as their investigative platform. They investigate the similarities and differences between using pneumatic and hydraulic power in the PFPD. With the main components of the PFPD already assembled, student groups determine the correct way to connect the valves to the actuators using colored, plastic tubing. Once connected, they compete in timed challenges to test their abilities to separate material out of containers using the PFPDs. NOTE: No special pre-requisite knowledge is required for students to be successful in this activity.

Students follow the steps of the engineering design process while learning more about assistive devices and biomedical engineering applied to basic structural engineering concepts. Their engineering challenge is to design, build and test small-scale portable wheelchair ramp prototypes for fictional clients. They identify suitable materials and demonstrate two methods of representing design solutions (scale drawings and simple models or classroom prototypes). Students test the ramp prototypes using a weighted bucket; successful prototypes meet all the student-generated design requirements, including support of a predetermined weight.

Students use their knowledge of scales and areas to determine the best locations in Alabraska for the underground caverns. They cut out rectangular paper pieces to represent caverns to scale with the maps and place the cut-outs on the maps to determine feasible locations.

Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

Waterwheels are devices that generate power and do work. Student teams construct waterwheels using two-liter plastic bottles, dowel rods and index cards, and calculate the power created and work done by them.

Students learn how engineers design devices that use water to generate electricity by building model water turbines and measuring the resulting current produced in a motor. Student teams work through the engineering design process to build the turbines, analyze the performance of their turbines and make calculations to determine the most suitable locations to build dams.

Students learn how engineers harness the energy of the wind to produce power by following the engineering design process as they prototype two types of wind turbines and test to see which works best. Students also learn how engineers decide where to place wind turbines, and the advantages and disadvantages to using wind power compared to other non-renewable energy sources.

Working in groups, students look at three different villages in various parts of Africa and design economically viable engineering solutions to answer the energy needs of the off-the-grid small towns, given limited budgets. Each village has different nearby resources, both renewable and nonrenewable. Student teams conduct research, make calculations, consider the options and create plans, which they present to the class. Through their investigations and planning of custom solutions for each locale, they experience the real-world engineering research and analysis steps of the engineering design process.

Students continue to explore the story of building a pyramid, learning about the simple machine called a pulley. They learn how a pulley can be used to change the direction of applied forces and move/lift extremely heavy objects, and the powerful mechanical advantages of using a multiple-pulley system. Students perform a simple demonstration to see the mechanical advantage of using a pulley, and they identify modern day engineering applications of pulleys. In a hands-on activity, they see how a pulley can change the direction of a force, the difference between fixed and movable pulleys, and the mechanical advantage gained with multiple / combined pulleys. They also learn the many ways engineers use pulleys for everyday purposes.

In this activity, students act as power engineers by specifying the power plants to build for a community. They are given a budget, an expected power demand from the community, and different power plant options with corresponding environmental effects. They can work through this scenario as a class or on their own.

This lesson provides students with an overview of the electric power industry in the United States. Students also become familiar with the environmental impacts associated with a variety of energy sources.

Students imagine they are stranded on an island and must create the brightest light possible with the meager supplies they have on hand in order to gain the attention of a rescue airplane. In small groups, students create circuits using items in their "survival kits" to create maximum voltage, measured with a multimeter and two LED lights. To complete the activity, students act as engineers by using the given materials to create circuits that produces the highest voltage and light up the most LED lights. They apply their knowledge of how voltage differs in a series circuit and a parallel circuit to design their solutions.

Students learn about the mechanical advantage offered by pulleys in an interactive and game-like manner. By virtue of the activity's mechatronic presentation, they learn to study a mechanical system not as a static image, but rather as a dynamic system that is under their control. Using a LEGO® MINDSTORMS® robotics platform and common hardware items, students build a mechanized elevator system. The ability to control different parameters (such as motor power, testing load and pulley arrangement) enables the teacher, as well as the students, to emphasize and reinforce particular aspects/effects of mechanical advantage.

Students read and evaluate descriptions of how people live "off the grid" using solar power and come to understand better the degree to which that lifestyle is or is not truly independent of technological, economic and cultural infrastructure and resources. In the process, students develop a deeper appreciation of the meaning of "community" and the need for human connection. This activity is geared towards fifth-grade and older students and Internet research capabilities are required. Portions of this activity may be appropriate with younger students.

Students use balloons (a polymer) to explore preconditioning a viscoelastic material behavior that is important to understand when designing biomedical devices. They improve their understanding of preconditioning by measuring the force needed to stretch a balloon to the same displacement multiple times. Students gain experience in data collection and graph interpretation.

This lesson culminates the unit with the Go Public phase of the legacy cycle. In the associated activity, students depict a tumor amidst healthy body tissue using a Microsoft Excel® graph. In addition, students design a brochure for both patients and doctors advertising a new form of painless yet reliable breast cancer detection. Together, the in-class activity and the take-home assignment function as an assessment of what students have learned throughout the unit.

Acting as civil engineers hired by the U.S. Department of Transportation to research how to best use piezoelectric materials to detect road damage, student groups are challenged to independently create their own experiment procedures, working with given materials and tools. The general approach is that they set up model roads using rubber mats to simulate asphalt and piezoelectric transducers to simulate the in-ground road sensors. They drop heavy bolts at various locations on the “road,” collecting data and then analyzing the voltage changes across the piezoelectric transducers caused by the vibrations of the bolt hitting the rubber. After making notches in the rubber “road” to simulate cracks and potholes, they collect more data to see if the piezo elements detect the damage. Students write up their research and conclusions as if presenting evidence to USDOT officials about how the voltage changes across the piezo elements can be used to indicate road damage and extrapolated to determine when roads need maintenance service.