system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What makes medical grade skin adhesive patches so sticky, and how are they able to stay in place for weeks at a time?
gpt
Really strong glue chemically bonds to the surfaces it's applied to.  Scientists found a glue that chemically mixes with the skin permanently.  

But it only reacts with the top layer of skin.  As your skin cells die off and shed, the chemically bonded cells are shed too.  

So when the patch comes off, it's not really the glue that wore off, but the skin it bonded to.