The Engineering Design Process: Aerogels
Author: Marjorie Langston
Source: The lesson is the original work of the author. This material is based upon work supported by the
National Science Foundation under Grant No. EFC-1542358
Research currently being done at the University of Akron involves the creation of a gel polymer emulsion to make aerogels. The emulsifying agent (and dissolved phase) in the gel cannot simply be evaporated out because the holes left behind in the gel will collapse. Thus, a multistep solution exchange process is performed to get rid of the emulsifying agent (and dissolved phase) and leave the pores (holes) left behind intact. The result is a solid with lots and lots of holes in it called an aerogel.
Aerogels have been used in recent years by NASA and other entities because they have unique properties like being of a very low density and being incredible thermal insulators. Though they are very useful, aerogels are not widely used because it is still expensive to manufacture them on a large scale.
In this lesson, students will mimic polymer/process engineers by designing a process to eliminate chocolate chips from chocolate chip cookie dough (their “gel”) without destroying the holes left behind. This is a STEM lesson is in which the engineering design process is taught. An engineering design notebook is provided as well as metrics (including required teacher signatures at various points and Self, Peer, Group Evaluations) for ensuring that all students are on task at all times. Further, this notebook makes assessing individual contributions to the cooperative assignments easier many other projects.
What should students know as a result of this lesson?
- Scientific Inquiry
- STEAM/21 st Century Skills—collaboration, communication, creativity, critical thinking, conflict
- The engineering design process
- The following terms: emulsion, emulsifying agent, compressive strength, aerogel, immiscible
- Macrostructure of aerogels; properties and uses of aerogels; how structure influences properties
and thus uses of a material
- That aerogels are important substances being researched at the University of Akron and NASA
What should the students be able to do as a result of this lesson?
- Explain/Define: the engineering design process, emulsion, emulsifying agent, compressive
strength, aerogel, issues with making aerogels
- Use the engineering design process and STEAM/21 st Century Skills (collaboration,
communication, creativity, critical thinking, conflict resolution, perseverance) to design a process
- List properties of aerogels
- Explain how structure affects properties which affects uses of a material
- Aerogel Sample ($30-$100)—can be purchased from http://www.buyaerogel.com/ or http://aerogeles.com/ . These samples are important. Alternatively, you could contact the
manufacturer as ask them to donate samples to your class. Also, you can contact the Akron
Global Polymer Academy to see if the research labs have samples they plan to throw away.
- 4-8 packages premade chocolate chip cookie dough (or supplies to make it) for a class of 24
working in pairs (2-4 samples each round per pair) ($8-$20)
- Basic lab supplies; basic household items like milk, oil, vinegar; cleaning solutions
- Access to a heat source (Bunsen burner, oven/toaster oven) is helpful
- Access to the internet and computers/tablets/smartphones/etc.; Google Slides, PowerPoint, or
other presentation software
- Supplies for liquid nitrogen demo or dry ice demo:
- Liquid Nitrogen: liquid nitrogen; liquid nitrogen gloves; items such as live flowers, a
racquetball and hammer, a balloon, grapes, scallions, etc. for a demo. A large cutting board (or work
surface) and a bucket or deep ceramic baking dish, can be purchased from thrift stores, etc., may be
- Dry Ice: dry ice, containers, indicator, bottle, tubing, cup with lid, etc. (See videos.)
- Note: Your local university or a private company may have science outreach programs that
bring liquid nitrogen to schools. Some even do the demos for you.
- Candy mixture to use to determine pairs/groups
A weeks prior:
- Ask your administration for a permission slip that will allow you use pictures of students working
and their work samples for edu
- Mention the engineering design challenge to students.
- Design a means for removing chocolate chips from chocolate chip cookie dough and leave the holes left behind intact.
- Tell students to be thinking of ideas and gathering supplies. Notify them that they will have a say
in the design constraints (what substances are they allowed to use/not allowed to use, if cost will
be a factor, etc.). Also, notify them that you will be choosing groups.
- View and plan your liquid nitrogen demo or dry ice demo. There are lots of videos on the internet
that you can use for ideas. Here are a couple:
- Liquid Nitrogen:
- Dry Ice:
Note: USE ETREME CAUTION WITH LIQUID NITROGEN AND DRY ICE
Handouts for almost assignments except the Pre and Post test are in the Engineering Design Notebook.
- Liquid nitrogen demo or dry ice demo.
- Intro: Aerogel Teacher Demo—Have a volunteer hold their eyes closed and hands out. Put an
index card in each hand and then an aerogel sample on one hand. Have student guess which
hand. To minimize concern, tell the class what you will do before you choose a volunteer. You
can let the students do this to each other. My students enjoyed trying to fool each other!
- Pre Test
- Mention design challenge again.
- Each day moving forward, have students watch 1-2 videos from the video list found at the end
of this lesson and start recording answers in the Basic Info Section (the first page) of their
Engineering Design Notebook.
- Note: Students must watch all videos to get all answers and some answers (i.e. uses, properties, etc.) are in more than one video.
- Second Note: One video references liquid nitrogen and another references dry ice so that
is why those demos are included in this unit.
- Post the entire video list in the Google Classroom, Drive, your teacher website, etc.
- Introduce/review problem and engineering design challenge by reading the paragraphs below
which is also in their Engineering Design Notebook:
- The Situation
When you shake a bottle of oil and vinegar salad dressing and look at it (before the layers
separate), you are looking at an emulsion. An emulsion is a heterogeneous mixture of two
immiscible substances dispersed in each other. Often an emulsifying agent is added to
prevent the layers from separating.
Aerogel research is currently being done at the University of Akron to create coatings for
clothing/masks which can filter out contaminants and thus improve our health. It is also
being done create better matrices for cells to grow on to fight disease, aid injuries, etc.
This research involves the creation of an aerogel by first creating a gel polymer emulsion.
Unfortunately, the emulsifying agent and dissolved liquid cannot simply be evaporated
because the holes left behind in the gel will collapse. Thus, multistep solution exchange
process is performed to get rid of them and leave the holes left behind intact. This involves
the sample being soaked in a solution for 24 hours, put into a (different) solution for 24 hours,
and then a third liquid for 24 hours before the sample is soaked and dried with supercritical
liquid carbon dioxide. The result is a solid with lots and lots of pores (holes) in it called an
Due to their unique structure, aerogels have many properties that make them very useful.
However, aerogels are not widely used because it is still expensive to make them.
Today, you are a polymer engineer. Your job is to start with a mixture and come up with a
means of eliminating part of the mixture without destroying the holes left behind. Your sample
“gel” is chocolate chip cookie dough.
- Have class come up with design constraints (what materials are allowed, how much of a
material is allowed, what lab equipment is allowed, etc.). Note: You may want to have
students not be able to remove the chips manually and to require that the cookie dough be in
its original shape at the end. Ironically, removing
- Have students complete the first box of the Imagine/Brainstorm Page of the Engineering
Design Notebook. Remind students that they will be able move on once every person has an
idea written on their paper.
- Handout a candy mixture. Students with the same candy type are paired with each other.
Pairs are preferred. Groups should not be larger than 3.
- Allow students to chat with their partner, come up with team names, and complete the rest of
the Imagine/Brainstorm page of the Engineering Design Notebook. Sign the pages. Note:
Signing is a means of making sure each person/group is on task and progressing. Also, it
allows you to quickly check work/provide feedback and input points later.
- Have students complete Project Planning Log. Sign the logs.
- From each day forward:
- Review the Introduction to STEAM, STEAM Habits of Mind, and Engineering Design
Process (See Attached Powerpoint). Maybe have it on playing on continuous loop on
the smart board.
- Have students watch 1-2 videos on aerogels/airloys and answer questions in Basic Info
Section of Engineering Design Notebook.
- Have students work on their challenge recording Lab Notes in Engineering Design Notebook
and taking pictures as they go.
- Over the next couple days, make extra copies of the rubric for the upcoming mini
- Turn to the Mini Presentation Rubric. Go through it with them in detail . Have students put
together a 4-8 slide presentation (less than 7 min). The topics to cover are listed below but are
also in the rubric. Tell students they will be graded by their peers as well as by you. I would
make this a very low key presentation.
- Have students complete Reflection portion of the Project Planning Log.
- Handout 3-4 rubrics to each team. Have them complete the top (names, team name, date).
Collect it and hand them out to audience members before each team presents so the audience
can also grade. Tell those who are grading to not put their name on the sheet they receive to
relieve social pressure.
- Hand out two different colored post-its to each table. Tell students that when they are not
grading, they will write team names and ‘one great thing about this project is . . .’ on one
colored post-it and ‘one thing to consider or one way to improve. . .’ on the other before
putting the post-its in a specific area of the room after each presentation. Have a
student/student aid check off each student as they turn in their comments to ensure all
participate. Note: Students must complete the post-its immediately following each
presentation otherwise they will forget. Also, you should complete each of your grade sheets
as soon as each group finished presenting for the same reason.
- Have each group present. Have 3-4 students grade. Choose different students each time to
grade. Remember to give students time to finish grading and writing on the post-its after each
- Have student aid hand out post-its to each group.
- About 7 min before class ends, give students time to put post-its on their Peer Feedback page
of the Engineering Design Notebook and to evaluate comments. group lessens some of the
- Allow class to evaluate their comments.
- Have the class decide on Redesign Constraints and record in notebook. Note: The new
constraints are only for the groups that accomplished the challenge in the first round. Those
that didn’t accomplish the goal still work under the original constraints.
- Allow students to brainstorm again, complete Brainstorm (Redesign) page and Project
Planning Log (Redesign) of Engineering Design Notebook. Sign logs.
- Redesign/Retest . Have students record Redesign Lab Notes and take pictures as they go.
- Prep for final presentation. Finish Reflection portion of Project Planning Log. Have
students make LinkedIn Page and link their presentation to it. A good (student) LinkedIn page will have
a professional headshot; a 1-3 sentence bio; work and volunteer experience; awards including
honors/AP/college classes, class rank, and GPA; and the project. Note: As of the writing of this lesson,
the Accomplishment Section has a section for awards, courses, and projects.
- Final Presentations with peer graders again
- Self, Group, Peer Evaluation
- Post Test
- Show and post to Google Drive, Classroom, Etc. the STEM scholarship/internship list.
Students will explain what they have learned and how they grew in STEAM/21 st Century Skills via the
Mini Group Presentation, Final Presentation/LinkedIn Page, and Posttest. Prior to that, they build
communication, creativity, and critical thinking through the brainstorming activity which requires that
they come up with ideas on their own, explain their ideas to their partner, and then, together, decide
which idea they will pursue. The students will also build communication/explanation skills via the Self,
Group, and Peer evaluation and Peer ‘Post-It’ Feedback Activity
Students will brainstorm other uses of aerogels including ways aerogels can improve lives on the
Basic Lab Safety. Knowledge of the term compressive strength/stress. Basic knowledge of a polymer is
helpful but not necessary.
Best Teaching Practices
- Wait Time
- Hands on/Minds on Learning
- Inquiry Approaches
- Using Analogies
- Graphic Organizers
Alignment with Standards
- Engineering Design
- Matter and It's Interactions
- Science Inquiry and Application
- Structure and Properties of Matter
The Engineering Design Process, 21 st Century Skills, Emulsions/solutions, Emulsifying agent,
Compressive strength, How to use PowerPoint/Google Slides, Internet research
Aerogels are substances that are more than 90% air which are being researched at the University of
Akron and other places because they have unique properties which make them very useful. However, an
inexpensive means of removing the excess matter from the gel (synthesizing the aerogel) on a large scale
has not been discovered. The students are engineers trying to discover a process for producing a
substance that has air pockets due to a substance having been removed from a solid just as
polymer/process engineers are.
Pretest. Basic Info Page. Brainstorming. Design Challenge Results. Lab Notes and Pictures. Mini
Presentation. Self, Group and Peer Review. Peer Feedback. Redesign Brainstorm. Redesign Challenge
Results. Final Presentation/LinkedIn Page. Posttest
- Students should work in pairs or groups of 3—maximum. Determine how many groups you will have.
Purchase a mixed bag of candy. Sort it so that you have only 2 (or 3) of each kind. Allow students to
choose the candy they want. Before eating, tell them that their partner is the person with the same candy.
Note: you will want to decide if the same candy but of a different flavor counts as the same candy or a
- The engineering design challenge (eliminate chocolate chips from chocolate chip cookie dough (their
“gel”) without destroying the holes left behind) can done as a one day mini challenge or as written with
engineering design notebook and individual assessments built in which takes just over two weeks. See
the ‘Procedure’ above.
Printable PDF Worksheets
Overview of Properties:
Videos the Highlight a Specific Property of Aerogels:
The Aerogel Synthesis Process
- Agnello Polyimide Aerogels - Weight Savers for Aircraft Antennae. A good summary of the
work being done at NASA which mirrors that being done By Dr. Sadhan Jana’s research group at
the University Akron. Highlights the work of a young female engineer. 2013. https://www.youtube.com/watch?v=DgkogPXG134 (2:16 min)
- How It’s Made—1336 Aerogel. A thorough summary though somewhat boring. 2017. https://www.youtube.com/watch?v=AlohrrK6u4k (5:60 min)