Intelligent developments are undoubtedly going to feature
strongly in the textile & fashion industries over the next decade and even
become a part of our everyday life. The so-called intelligence arises from the
incorporation of particular components into the fabric, which may be electronic
devices, specially constructed polymers or even some type of colorant. Many
intelligent textiles are designed to respond to adverse conditions in their
environment and there by provide enhanced protection. They can also either
alter their nature in response to external factors or confer additional
benefits to their users. There has been extensive innovation, for example, in
clothing fabrics that can provide extra insulation in hot as well as cold
conditions. Such textiles are becoming increasingly important in the fashion
industry.
The first question, which may be asked, is what exactly is
all weather clothing? A more technical term will be temperature-regulated or
thermo-regulated clothing. To consider thermo regulation only as staying warm
would be incorrect, or only half correct. The term is broader than that and
actually means maintaining the body temperature to the level that will maximize
performance and comfort, while also protecting the user. Temperature regulation
or thermo-regulation is best defined by its goal, which is to maintain both the
core body temperature and the comfort of the wearer in diverse environments.
The body itself regulates its temperature through a group of biological
processes. Even at rest the human body is a mass of ongoing chemical reactions
that regulates body heat within an optimum temperature range called the
thermo-neutral zone (usually set at 37+1oC). When the body temperature
extends beyond the limits of the thermo-neutral zone, bodily systems operate
less efficiently, and when pushed to extremes can even result in death.
Therefore, thermo-regulation is critical both from a safety and performance
standpoint.

Typically, fabrics do not inherently provide
thermo-regulation. Their thermo-regulation is affected by not inhibiting or
rather supporting the thermo-regulation efforts of the body itself. The role of
the fabric will be to allow air to circulate around the body and at the same
time provide a cushion of insulation (either hot or cold) when the body needs
it. The fabric must be able to adjust to the needs of the body over a wide
range of external temperatures and activities.
Certain combinations of fabric construction, chemical
finishes and garment construction can also keep the body warmer or cooler,
depending on the environmental conditions. Usually fabrics are geared for one
or the other. Cold weather garments must address both radiant and convective
heat loss. On the other hand, warm-weather garments must aid evaporative heat loss
by increasing moisture movement, and increasing the velocity of heat conduction
through the material. Control of airspace in the microclimate between the skin
and the garment, or between layers is of prime importance.
There are three main characteristics that have been observed
in materials that provide thermo-regulation. First is breathability/moisture
management. The absorption and retention of water must be as close to zero as
possible and there should be a mechanism to ensure that the moisture is moved
away from the skin. The second characteristic is insulation. The fabric must
have a good insulation value to supplement the boundary layer or air gap on the
surface of the skin. There can be a mechanism to vary the degree of insulation.
Last of all, the fabric must be lightweight with good bulk to achieve maximum
comfort.
Some of these characteristics and materials displaying them
are discussed below: