LunaMicro's textile pump technology sandwiches a nanoporous membrane (light blue) between electrodes (light purple) coated onto customer-selected materials (dark purple), creating a thin, flexible multi-layer textile.
Unlike passive solutions (like Gore-Tex), our technology moves liquid water, not just water vapor, and works even when the garment or surface is wet on the outside. That means your rain jacket will still let moisture out, even when it's raining.
Using industry-standard techniques and commercially-available materials, we print conducting polymer electrodes onto the customer's choice of inner and outer materials (dark purple in the picture). We then laminate these electrodes onto opposing sides of a nanoporous membrane, creating a multi-layer stack that feels like any other 3-layer membrane textile.
When a small battery is connected to the printed electrodes, the fabric transports water from one side to the other, wherever it is wet. Our material pumps liquid water from the inside of the fabric to the outside, even when the outside is wet, unlike "breathable" fabrics, which only "breathe" water vapor when it's dry outside. Our technology pumps water so rapidly that a jacket should only need a strategically-placed A4-sized "patch" of active pumping textile to keep the wearer dry.
Active versus passive moisture transport
Finding values that accurately describe how well a textile releases moisture is tricky. There are several standards for passive materials, but many of them measure transport when the outside environment is completely dry (0% external humidity). This is reported as grams of water transported per square meter of the material per 24-hour day (g/m2 /day). Since the difference in humidity between the inside and the outside of the garment is what drives moisture through a passive membrane, the rate of water transport will be much smaller when it’s humid outside. When the humidity outside is as high as the humidity inside the garment, the passive materials will stop “breathing” entirely.
We have summarized some values extrapolated from those reported by the US Army SoldierSystems Center Material Science team on state-of-the-art passive materials alongside our own measurements of our pumping laminate in the following table. The table includes the values for when it’s completely dry outside the garment (0% external humidity), and when the outside of the garment is wet (100% external humidity).
Device performance figures
Water transport at 0% external humidity
Water transport at 100%
|Luna Micro´s pumping laminate||Yes||20 000 g/m2/day||12 000 g/m2/day|
|GORE-TEX (ePTFE) membrane||No||6 500 g/m2/day||Insignificant|
|GORE-TEX laminate||No||3 000 g/m2/day||Insignificant|
|Sympatex laminate||Yes||1 500 g/m2/day||Insignificant|
Sources: LunaMicro's performance calculated using internal laboratory measurements. GORE-TEX and Sympatex values from a report by the US Army Soldier Systems Center Materials Science team.
We've targeted the sports clothing and equipment market for our first products since it is lucrative and has relatively few barriers to entry. We often use a water-resistant jacket (shell) as a typical application for our technology even if many of our customers have identified other preferred products for our technology.
An example of an early prototype of a jacket with LunaMicro's pump technology. The black patch is the pump.
A textile pump about the size of an A4 sheet of paper is, in most circumstances, sufficient to transport the sweat that an active person can produce. As such, a garment can be made with "traditional" natural or synthetic waterproof or water-resistant materials, and the water transport requirement can be met by a pump strategically placed to remove as much moisture as possible. In many cases, this is on the back of the garment, between the wearer's shoulder blades.
Rendering of a potential future garment design and our latest electronics box which fastens on the inside of the jacket with snaps.
The electronics that drive our pump can take on many forms. To demonstrate our technology, we have developed self-contained "boxes" that can be installed in a garment. Each box contains the electronics to drive the pump and communicate with a nearby device such as a computer or telephone (via low-energy Bluetooth, BLE) and a rechargeable battery that will likely last two to three days in the field. This box has four "snaps" that provide electrical connections to the pump (via wires installed in the jacket) and hold the box to the inside of the garment. When the box is removed (unsnapped), the garment can be washed.
The removal of the box also facilitates the recycling of the electronic components and battery contained therein, as well as the recycling of the garment, at the end of the device's / garment's life cycle.