This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Applying eyedrops is difficult in space, where there is almost no gravity. A KAIST research team has developed a wearable patch that delivers eyedrops to the eye without relying on gravity.
The research team was led by Professor Ki-Hun Jeong from the Department of Bio and Brain Engineering, in collaboration with a research team led by Professor Se Joon Woo from Seoul National University Bundang Hospital. The paper is published in the journal Sensors and Actuators B: Chemical. During long-duration space exploration, technologies that allow astronauts to manage their health without direct help from medical staff are essential.
In particular, microgravity causes body fluids to shift toward the head, which can change the structure of the eyes and visual function. However, the standard method of applying eyedrops on Earth depends on drops falling by gravity, so it cannot be used in space without modification. The research team combined microchannels that carry liquid with a chemical reaction chamber that generates pressure, all in a single flexible patch.
When the user wears the patch and presses the actuation area, the pressure of the gas generated inside delivers the eyedrop to the eye. The patch works through a reaction between vitamin C and baking soda. When ascorbic acid (vitamin C) and sodium bicarbonate (the main component of baking soda) come into contact with water, carbon dioxide gas is produced.
The resulting pressure pushes the eyedrop along the microchannel. Instead of relying on gravity to move the eyedrop, the patch uses pressure generated inside it. A filter placed between the reaction chamber and the eyedrop chamber allows gas to pass but blocks liquid.
This keeps the reactants and the eyedrop separate while still transmitting the gas pressure. Because the patch needs no external pump or electrical drive, it is expected to be suitable for settings where equipment is limited. The research team confirmed that the patch released eyedrops consistently even when the direction of gravity was changed.
Extract — continue reading at the source.
