Osmotex Advanced Membrane

In addition to micropumps, Osmotex has developed an electroosmotic membrane, which can be described as an electric powered breathable fabric or textile pump. One square meter of membrane can actively pump up to 200 liter per square meter and hour. The power consumption in  typical applications will be a few W. Water transport rate and direction is controlled electronically and the device normally be powered by a small battery. The EO textile was invented and patented as a response to the gap between human perspiration rates (can easily exceed one liter per hour during vigorous activity, some times several liters) and the ability of current breathable clothing to transport the humidity away (typically less than 0.3 liter per hour and square meter).

Even a thick jacket made of the EO textile and inner wicking layers should assure perfect comfort and dryness during hard exercise or work. By allowing perspiration water to escape, the body's temperature regulation is allowed to function unhindered. The high transport rates imply that only smaller parts of the jacket need to contain the EO membrane.

The product fits within the trend of endowing textiles with advanced functionalities such as heating, medical and other sensors, pushbuttons and wiring for ipods and mobile phones.

Possible applications include

• Breathable sports clothing and equipment such as tents, sleeping bags
• Protective clothing for firefighters, military personnel etc
• Seat covers in cars, aeroplanes etc (to avoid dampness)
• Medical applications (bed linen, humidity controlled sensors and electrodes for EKG etc)
• Tarpaulins and tents for storage and transportation
• Protecting electronic, photographic and other delicate equipment

Real time video showing EO textile in action.

FUNCTIONAL CLOTHING

Present breathable clothing can only transport 1-3 dL of water per hour, depending on weather conditions. In warm and humid conditions, this transport goes to zero.

Perspiration- and work rates at different activity levels are indicated in table 1. In more extreme cases, sweat rates of several liters per hour have been measured for firefighters and athlets. When the clothing is not able to transport the perspiration water away, the wearer's performance drop steeply and one risks conditions of hypo- and hyperthermia in extreme situations.

Table 1. Work- and Perspiration Rates Under different Activities (Coated Fabrics, 1985).

The 3-layer Osmotex textile is capable of transporting more than 1 liter per hour with energy from a small battery. Table 2 lists transport rates for standard breathable clothing, along with Osmotex' fabric.

Table 2. Performance of Waterproof Breathable Fabrics: (P.Salz et.al. Philadelphia 1988, p295). 

The Osmotex membrane transports water in the liquid phase, at rates up to tens of liters per square meter and hour. The flow rate and direction is controlled by the electric signal, and does not depend on outside temperature and humidity.

New 20 micron thick membrane with integrated electrodes. The steel grid on top is a detachable electrical connector (much smaller connectors can be used). The video shows cycles of drying and pumping water back from the under side.

(See Textile pump)