The photograph is of a water-swollen hydrogel particle created in our chemistry laboratory, taken with an instrument called a Scanning Electron Microscope, which allows us to zone in and see important details on the surface of the hydrogel. A hydrogel is essentially a plastic material that is able to absorb very large volumes of water (up to 800 times its weight!) – much like a baby diaper, swelling as it does so. From the image, the surface of the hydrogel is seen to possess large, distinctive pores, which help us understand how and why hydrogels absorb so much liquid.