How a Pandemic Experiment Brought Biomaterials Home
When COVID-19 shut down laboratories, educators developed an ingenious at-home experiment using paperclips and saltwater to teach metal corrosion—a fundamental challenge in medical implants.
Explore the ResearchImagine a tiny metal screw holding a broken bone together inside the human body. Now imagine that same screw slowly dissolving over time, releasing metallic particles into the bloodstream. This isn't science fiction—it's the real-world challenge of metal corrosion that biomedical engineers work to solve every day.
When the COVID-19 pandemic shut down laboratories and classrooms, educators faced an unprecedented question: How do you teach hands-on engineering concepts when students can't access labs?
The answer emerged from an unlikely combination of paperclips, saltwater, and household items that would eventually transform STEM education for underserved communities.
When universities and schools abruptly shifted to online learning in March 2020, the hands-on experimental component of STEM education became a major casualty 4 . Laboratory courses that depended on specialized equipment were particularly vulnerable.
The situation exposed and exacerbated existing educational inequalities. Research revealed that students from underrepresented groups were differentially impacted by the shift to online learning, particularly with regard to access to study spaces, reliable internet, and peers 7 .
In response to these challenges, a team of educators from the Icahn School of Medicine at Mount Sinai and The Cooper Union for the Advancement of Science and Art developed a series of inexpensive at-home experiments for undergraduate engineering students 1 .
They adapted one of these experiments—focused on metal corrosion—for middle school students in the Young Eisner Scholars (YES) Program, which serves diverse, underserved communities across the United States.
The experiment focused on a crucial question in biomaterials: How does the saline environment of the human body affect metal medical implants?
The experiment was conducted in two virtual sessions over five weeks, maintaining the social and collaborative aspects of laboratory science while allowing for remote participation.
The beauty of this experiment lies in its simplicity and accessibility. Using common household items and materials costing approximately $1 per student, participants investigated how different solutions affect metal corrosion 1 .
Preparation & Surface Treatment
Solution Preparation & Setup
Observation & Analysis
Students received kits containing nitrile gloves, smooth paperclips, assorted grit sandpaper, and disposable plastic cups. They provided their own tap water, salt, and permanent markers 1 .
The galvanized coating was removed from paperclips by sanding them. This step, called depassivation, allowed corrosion to occur more readily, mimicking the active surface of a medical implant 1 .
Three solutions were prepared in separate cups:
| Solution | Preparation | Relevance to Biomaterials |
|---|---|---|
| Tap Water | Straight from faucet | Control environment; represents pure aqueous solution |
| Dilute Salt Water | Approximately 0.9% salt | Similar salinity to human blood and body fluids |
| Concentrated Salt Water | Saturated solution | High-ion environment that accelerates corrosion; tests extreme conditions |
After five weeks of immersion, clear differences emerged between the paperclips in various solutions. Students observed that paperclips in salt solutions showed significantly more corrosion than those in plain water, with the most severe damage occurring in the concentrated salt solution 1 .
The fatigue testing yielded even more insightful quantitative data. When students repeatedly bent the corroded paperclips, they discovered that corroded metals failed more quickly than non-corroded metals.
| Solution Type | Average Number of Bends to Failure | Relative Corrosion Severity | Implication for Medical Implants |
|---|---|---|---|
| Tap Water | Highest | Mild | Longer service life |
| Dilute Salt Water | Medium | Moderate | Reduced mechanical longevity |
| Concentrated Salt Water | Lowest | Severe | Potential premature failure |
This experiment succeeded because it transformed abstract concepts into tangible experiences using accessible materials. Each component served both a practical and educational purpose.
Function: Test subject
Scientific Principle: Metal specimens with consistent composition and geometry
Function: Corrosive environments
Scientific Principle: Effect of ion concentration on electrochemical reactions
Function: Surface preparation
Scientific Principle: Removal of passivation layer to enable corrosion
Function: Personal protective equipment
Scientific Principle: Safety protocol in scientific investigation
The success of this simple experiment points to larger possibilities in STEM education.
Demonstrated that meaningful hands-on science can be accessible and affordable at just $1 per student.
Showed benefits for outreach to diverse communities by eliminating geographical barriers.
Highlighted the value of meeting students where they are—both literally and figuratively.
The at-home metal corrosion experiment represents more than just a temporary solution to an unprecedented educational disruption. It demonstrates how constraints can spark creativity, leading to innovations that ultimately make STEM education more inclusive and accessible.
By transforming kitchen tables into laboratories and paperclips into medical implants, educators managed not only to maintain student engagement during a challenging time but potentially to inspire a new generation of diverse biomaterials researchers.