1. Engineering Bio-Plastics:
Understanding Natural and Synthetic Materials Using a Hands-on Lab
Megan Bradfield
Paw Paw High School
Abstract
Project Description
Assessment of Project
Students designed their own bio-plastic recipe to replace a plastic product of their choice. Students were required to use the Engineering Design Process during the production of an initial and a second prototype of their bio-plastic. This project was incorporated into instruction to help student understanding of the comparison between natural and synthetic resources as well as the impact of synthetic resources on society.
Students were first pre-assessment to assess prior knowledge of the content. Then students were given traditional instruction on the relationship between natural resources and synthetic materials before being assessed at a mid point to assess the effectiveness of traditional instruction. Then they were given the task of designing a bio-plastic prototype recipe that can be used to replace a non biodegradable plastic item used in everyday life. After developing their own recipe then they were to modify the prototype recipe to optimize the plastic created using the first prototype recipe. Students had to create their own recipe after creating two plastics using demonstration recipes. Students also recorded their recipes and observations in an engineering journal.
Constraints: Use only the provided corn starch, gelatin, water, glycerol, vinegar, and food coloring. Students must also have part of their plastic poured onto a watch glass to make a flat sample.
Students completed an Engineering Design Notebook which included:
-Initial Recipe
-Observations and Drawing of First Prototype
-Final Recipe
-Observations and Drawing of Second Prototype
Students also took pre, mid, and post assessments concerning the content area covered during the unit and lab.
Additionally, students were given surveys to assess their self efficacy and attitudes towards science.
WV NxGen Standards
MS-PS1-3/ S.8.PS.2: Gather and make sense of information to describe that synthetic materials come from natural resources and impact society. 
S. 6-8.ETS.2-evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
Engineering Design Products
Project Timeline
45- minute, M-F class periods.
Timeline
Teaching
Week 1, Day 1
Students will take the pre-quiz and surveys to assess prior knowledge and areas of weakness to be improved upon.
Week 1,
Day 2-3
Introduce Natural and synthetic materials
Students will read an article and watch videos detailing examples of and comparisons between natural and synthetic resources. Class will discuss the article and videos.
Day 4
Read article concerning trans fats. Discuss negative effects of synthetic products on society.
Days 5
Students read article on blue jean dye and jean production. Discuss positive uses of synthetic resources.
Week 2,
Day 6
Students will take the mid-quiz and surveys to assess their knowledge after traditional instruction.
Day 7
Students will work in pairs to make their first demo plastic using the cornstarch recipe.
Day 8
Students will work in pairs to make their second demo plastic using the gelatin recipe with jello.
Day 9
Students will work in pairs to make their third demo plastic using the gelatin recipe. This time using unflavored gelatin instead of Jello.
Day 10
Students will assess their first experiments and develop their own recipe using the ingredients from the demo recipe experiments.
Week 3,
Day 11
Students will create their bio-plastic using the recipe they designed.
Day 12
Students will assess their bio-plastic and modify their recipe to make the plastic more to their desired product.
Day 13
Student will perform a second trial where they will test their second recipe.
Day 14
Students assessed their final product and compared it to their first product and the demo plastics.
Day 15
Students took the final assessment and surveys.
Students poured part of their plastic recipe into a watch-glass to make a flat sample and were able to either pour out the rest onto wax paper or allow to cool in a beaker as a mold.
One student tested what the addition of gelatin changes about the cornstarch recipe and then removed the gelatin and increased glycerol amount for his second prototype shown above.
The teams of students created demonstration bio-plastics using two different methods to help them develop their own recipe.
Evaluate/Reflect
One of the first needs for modification I found was that that regular Jello did not work as well and that unflavored gelatin was required for a usable product that students could make. The sugar in the Jello product seemed to interfere with the plasticizing of the gelatin.
The students really seemed to enjoy the lab and their content quiz results support that the project improved their performance. The surveys, however, showed a positive trend with some students and a negative with others. Within, the classroom the students did not seem to care about their scores on the survey which is something that I look to improve on for the future. I also think that this project helped me connect with this class of students and creating a rapport.
Overall, the majority of the students really liked the project and felt like the content was more relevant to them.
Students were able to add color to their plastics to personalize and take ownership of their prototypes.
Students progressed from the cornstarch recipe, to the gelatin recipe, to their first prototype recipe, and then to their last recipe.
Acknowledgements
I would like to thank my amazing students for their hard work and cooperation on this project and my ESS Passport cohort for all of their support and feedback. My administration at Paw Paw High School were also supportive and receptive to my project.