Slippery When Wet: Investigating the friction of pH-sensitive hydrogels

Interns

Callie Thai, Emily Ngo, Lily Campbell, and Ozair Usmani

Project Description

With numerous inventions enhancing the quality of everyday life, contacts, a type of hydrogel, are a vital product for sight. Unfortunately, contacts block the mucin layer in the eye, disrupting the layer’s lubrication and possibly irritating the user. We plan to prevent this issue by exploring hydrogels, a gel-like material that absorbs water like a sponge, to create contacts that mimic the mucin layer. Hydrogels can change their properties based on different stimuli; one of these stimuli is pH. We aim to learn how the friction of these gels will react to pH and incorporate that information to create safer, non-pH-responsive hydrogels. We created hydrogels that swelled in three different pH solutions (acidic, basic, and neutral) and measured the pH-induced friction of these gels. These results allowed us to compare the various frictions to see which hydrogel was more slippery. We found that more basic solutions developed a lower friction while more acidic solutions developed a higher friction. With these discoveries, we plan to work towards creating safer contacts and explore other stimuli that may affect hydrogel properties.

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