Although this is a bio class, I was really interested in observing something nonliving (that had once been alive) under the microscope: paper. Looking directly at a piece of paper with out Foldscopes would be difficult – even at a thickness of only 1/10 of a mm it simply blocks out too much light – but I thought it might be possible to observe the edge of a piece of paper.

Indeed, after placing two pieces of paper (normal and carbon copy) on a slide and covering them with a glass coverslip, and a bit of panning and fiddling with the focus ramp, an otherworldly scene came into view.

The paper fibers, weaving and twisting around each other, looked remarkably like matted human hairs! It was pretty surreal to pan along the edge of the paper, looking at the different patterns that appeared. I was interested as to the composition of these fibers, and it turns out that in the process of pulping during papermaking, the cellulose in wood is separated from lignin, which generally doesn’t go into paper, since it deteriorates over time. Most trees are slightly less than 50% cellulose, so the goal of pulping is to isolate it from other impurities in the tree. It’s this cellulose that forms the long polysaccharide fibers in paper pictured above, through covalent bonding between the monosaccharides and hydrogen bonding between adjacent chains. This was the edge of the normal paper that had been ripped by hand, so next I decided to take a look at the artificially cut edge to see how different it might appear.

Very different! Although there were plenty of imperfections on this side of the paper, it was much, much smoother than the ripped side. It’s surprising to think that this flimsy-looking edge can cut through human skin! Next, I took a look at the ripped edge and cut edge of carbon-copy paper.

This is the corner of the paper, so it shows both edges next to each other for a sense of scale. It’s clear that ripping allows for the fibers to become separated from each other and actually observable, while cutting during papermaking keeps the fibers relatively compact. There didn’t seem to be much of a difference between the two types of paper, although the fibers in the normal paper did seem to be a bit longer and messier than the ones in the carbon-copy. Although, paper might not be alive, it’s a world on its own that’s fascinating to observe!