We’ve always been interested in fluidic computers, a technique that uses moving fluids to perform logic operations. Now, Spectrum reports that researchers have developed an electronics-free contact lens that monitors glaucoma and can even help treat it.
The lens is made entirely of polymer and features a microfluidic sensor that can monitor eye pressure in real time. It also has pressure-activated drug reservoirs that dispense medicine when pressure exceeds a fixed threshold. You can see Spectrum’s video on the device below.
This isn’t the first attempt to treat glaucoma, which affects more than 80 million people, with a contact lens. In 2016, Triggerfish took a similar approach, but it used electronic components in the lens, which poses problems for manufacturing and for people wearing them.
Naturally, the device depends on 3D printed molds to create channels and reservoirs in the lens. A special silk sponge in the reservoirs can absorb up to 2,700 times its weight. One sponge holds a red fluid that is forced by pressure into a serpentine microchannel. A phone app uses a neural network to convert the image of the red fluid into a pressure reading.
Two more sponges hold drugs that release at a given pressure determined by the width of the associated microchannel. This allows the possibility of increasing the dose at a higher pressure or even delivering two drugs at different pressure levels.
It is fairly hard to hack your own contact lenses, although we’ve seen it at least once. But smart contacts are not as rare as you might think.