This document provides an overview of smart and intelligent textiles. It defines smart textiles as textiles that can sense environmental stimuli and react or adapt in response through the integration of functionalities into the textile structure. Smart textiles are classified into three categories - passive, active, and ultra smart - based on their functional activity of sensing, reacting, and adapting. Examples of applications for smart textiles include military, healthcare, space exploration, and fashion. The document also discusses phase change materials and how they can be incorporated into textiles to provide thermoregulation properties for applications such as sportswear, bedding, and medical uses.

1. INTELLIGENT AND
FUNCTIONAL TEXTILE
MODULE-1

2. Concept of Smart Textiles:
Textiles are considered as the second skin of humans. Protection and aesthetics are two
common
dimensions associated with textiles. Third dimension, intelligence is being integrated into
fabrics to produce interactive textiles. Last few decades have shown enormous growth in the
development of wireless communication, Nano engineering, information technologies and
miniaturization of electronic devices. The world is distinctly rising towards the era of smart and
intelligent textiles. This new class of smart and intelligent textiles is being designed to meet
new and innovative applications in following fields:
• Military/Defense
• Medical/health care
• Space exploration
• Sports
• Fashion and entertainment.

3. What does it mean exactly, ‘smart textiles’?
• Textiles that is able to sense stimuli from the environment, to react to them and adapt to them
by integration of functionalities in the textile structure. The stimulus as well as the response
can have an electrical, thermal, chemical, magnetic or other origin.
• Advanced materials, such as breathing, fire resistant or ultra-strong fabrics, are according to
this definition not considered as intelligent, no matter how high technological they might be.
The first applications of smart textiles can be found in clothing.

4. Types of Smart Textiles:
Smart textiles can be classified in three categories according to its functional activity. They are as
follows:
• Passive Smart Textile:
Passive Smart textile is the first generations of smart textiles, which can only sense the environmental
conditions or stimuli known as sensor. UV protective clothing, multilayer composite yarn and textiles,
plasma treated clothing, ceramic coated textiles, conductive fibers, fabrics with optical sensors are
some examples of passive smart textiles.
• Active Smart Textile:
Active Smart Textile is the second generation which has both actuators and sensors. The actuators act
upon the detected signal either directly or from a central control unit. Phase change materials and
shape memory materials, heat sensitive dyes, etc. are examples of active smart textiles.
• Ultra Smart Textile:
It is also known as Very smart textile. It is the third generation of smart textiles, which can sense, react
and adopt themselves to environmental conditions. A very smart textile essentially consists of a unit,
which works like the brain, with cognition, reasoning and activating capacities. For example,
spacesuits, musical jackets, I-wear, data wear, sports jacket, smart clothes, wearable electronics etc.

5. The smart textile has five functions to complete its full works.
They are:
Sensors- It captures parameter from the environment.
Data Processing- It is required when active processing is necessary.
Actuators- It responds by the resulting function of sensor.
Stimulation - It is found from the environment.
Giving Response- From the actuators it gives response.

6. Phase change materials (PCMs)
• Now days, phase change materials are highly applied in the field of textiles for
different kinds of
products such as apparel, underwear, socks, shoes, bedding accessories and sleeping
bags. For
multifunctional products also are applicable in the specialty items like anti-ballistic
vests,
automotive, medical or for other industrial applications.

7. Incorporation of PCMs in textiles
The PCMs change phases within a temperature range just above and below human skin
temperature would be suitable for application in textiles. This interesting property of PCMs
would be useful for making protective textiles in all-season. Fiber, fabric and foam with
PCMs could store the heat body creates then release it back to body, as it needs. Since the
process of phase change is dynamic; therefore, the materials are constantly changing from a
state to another depending upon level of physical activity of the body and outside
temperature. The thermo-regulating characteristic is possible in manmade fiber by adding
PCM microcapsules to a polymer solution prior to fiber extrusion. In the process, PCM
microcapsules are integrated inside the fiber itself. Coating, lamination, finishing, melt
spinning, bi-component synthetic fiber extrusion, injection molding, foam techniques are
some of the convenient processes for incorporation of PCMs into the textile matrix.

8. Application of PCMs in Textiles
• Space
• Sports wear
• Bedding Accessories

9. • Medical Applications
• Automobile application
• Self Cleaning Textiles

10. Heat Balance:
Normally the body temperature is about 37 degree C. This value is achieved by
balancing the amounts of heat produced in the body with the amounts lost
In most climates body temperature is above that of the external environment
so that there has to be an internal source of heat in order to maintain the
temperature difference.
● The required heat comes from the body's metabolism, that is the necessary
burning of calories to provide power to muscles and other internal functions.
● However, the body must be kept in thermal balance: the metabolic heat
generated together with the heat received from external sources must be
matched by the loss from the body of an equivalent amount of heat.
● If the heat gain and the heat loss are not in balance then the body
temperature will either rise or fall, leading to serious threat to life.
● The efficiency of the human organism is such that of the energy taken in as
food only 15-30% is converted into useful work with the remaining 70-80% of
the energy being wasted as heat.

11. Thermo physical Comfort:
The clothing is not worn only for protecting the human body, but it helps to
obtain comfort during high level activities or in unfavorable environmental
conditions. Heat generated by the working human body in hot climate or high
physical activity, which must be dissipated to the environment. Similarly, in
the cold environment, the body is going to be shielded from cold feeling.

12. Thermoregulation through clothing
system
By the metabolic processes, the human body continuously generates heat. The warmth is
lost from the surface of the body by convection, radiation, evaporation and respiration. In
a steady state condition, the heat produced from the body is balanced through the heat
loss to the environment. The body has very intelligent thermoregulatory system to make
sure the body core temperature (37˚C). When the body heat increases higher than the set
value, vasodilatation of blood vessels is activated to increase the blood flow to the skin
for the aim of accelerating heat loss. If the body heat continues to rise, the sweating
mechanism will be activated to accelerate heat loss by evaporation of the liquid sweat. In
contrast, when the body detects its temperature decreased less than the set value,
vasodilatation of blood vessels is going to be activated to decrease the blood flow to the
skin to reduce heat loss, and metabolic rate will be increased by stimulating the muscles,
which ends up in shivering.
The thermoregulation mechanism through clothing depends primarily on the thermal
behaviors in human body and transmission characteristics of clothing and can be
summarized as:
• The biological thermal activities in the human body.
• The heat transmission through clothing.

13. THE END