Today’s wearable technologies that incorporate conduits with high-pressure fluids that need to be pumped typically require a large, noisy pump that is impractical (or impossible) to integrate into clothing. This leads to a contradiction: wearable devices need to be connected to non-wearable devices. Now, scientists have come up with a revolutionary breakthrough that will solve that problem.
Herbert Shea’s team, from the Federal Polytechnic School of Lausanne in Switzerland, has made the world’s first bomb in the form of fiber; essentially, a set of tubes, like arteries, that generates its own pressure and regulates the flow. Such a unique bomb can be sewn into fabrics and thus be fully integrated into clothing. In addition, it supports washing with water and conventional laundry detergents.
The new pump builds on Shea’s lab’s pioneering experience in inventing soft bombs. The fiber format makes it possible to make pumps as powerful as conventional ones but lighter, which are much more compatible with wearable devices.
The physical principle on which the new pump is based is known as charge injection electrohydrodynamics. And it allows you to generate a fluid flow without moving parts. Two helical electrodes built into the wall of the pump ionize and accelerate the molecules of a special non-conductive liquid. The ionic movement and shape of the electrodes generate a net forward fluid flow, resulting in quiet, vibration-free operation, requiring only a small battery as a power source.
To achieve the peculiar structure of the bomb, the researchers developed a novel manufacturing technique that involves twisting copper wires and polyurethane threads and then fusing them together with heat. The resulting 2mm thick fibers can be integrated into fabrics using standard weaving and sewing techniques.
The photo shows part of a fiber pump sewn to a garment. (Photo: © LMTS EPFL)
The simple design of the pump has several advantages. The necessary materials are cheap and readily available, and the manufacturing process can easily be scaled up on an industrial scale. As the amount of pressure generated by the pump is directly related to its length, the tubes can be cut to suit each application, thus optimizing performance and minimizing weight.
Among the potential applications of these fiber pumps, it is worth noting that they can be used to circulate fluids that heat clothes when it is cold or cool them when it is hot.
The new pumps can also be used to generate mechanical activity, like muscles, in soft exoskeletons to help patients move and walk.
The temperature regulation and mechanical activity of these pumps could also be used to increase the range of tactile sensations in virtual reality video games.
Shea and his colleagues discuss the technical details of their new class of pump in the academic journal Science, under the title “Fiber pumps for wearable fluidic systems.” (Fountain: NCYT by Amazings)