Textile-based actuators

This chapter has three main sections. The first section gives an overview of the current state of the art on textile electrodes and their working principles. Section 2.3 summarizes the advances in textile sensors. Finally, the third section concentrates on textile-based actuators for medical applications, including textiles used for heating, electroflierapy and artificial muscles. 

What textile-based actuators are (or can be) used for in health applications ... 

Morris, D., Coyle, S., Wu, Y., Lau, K.T., Wallace, G., Diamond, D., 2009. Bio-sensing textile based patch with integrated optical detection system for sweat monitoring. Sens. Actuators... 

Textile electronics is another exciting area of apphcation. Fibrous diodes and transistors have already been developed in different laboratories. Flexible sensors and actuators (textile displays, heating fabrics) will in the future be part of our clothes, car interiors and home textiles. Therefore, flexible textile-based electronic circuits will be fully integrated to fabrics and connected to databases and servers making possible new ways to utilize clothing and other textiles. 

In the medical field, many textile-based devices using piezoelectric materials as sensors and actuators have been developed. A medical ECG chest, sleep monitor, patient care tremor suppressor, and breast cancer detection bra are some of the many devices that employ various forms of piezo materials. Several portable types of health monitors... 

As is the case for smart materials, intelligent textiles have the property to respond to their environment, sometimes in a clearly perceptible way, but sometimes at the molecular level, completely invisible to the observer. They cover a wide range of technologies, from materials with shape-memory properties or sensing and actuating properties, to entire systems based on information technology5. 

Functional fibres, filaments and yams are the basic building blocks of electrotextiles. The textile industry has demonstrated a remarkable capability to incorporate both natural and man-made filaments into yarns and fabrics to satisfy a wide range of physical parameters which survive the manufacturing process and are tailored to specific application environments. Electronic components can be fabricated within and/or on the surface of filaments and can subsequently be processed into functional yams and woven into fabrics. Passive components such as resistors, capacitors and inductors can be fabricated in several different manners. Diodes and transistors can be made on long, thin, flat strands of silicon or formed in a coaxial way. Progress has been made in the development of fibre batteries and fibre-based solar cells. In addition, a variety of actuated materials (piezoelectric, etc.) can be made into multiple long strands (filaments) and subsequently be woven into fabric. 

The health care industry is capitalizing on new medical technologies based on loT that will both dramatically improve care and lower costs. There is a dramatic growth in medical devices that use wireless technologies, some implanted and some worn on the body, to control bodily functions and to measure an array of physiological parameters. For example, implanted devices with biosensors and actuators can control heart rhythms, monitor hypertension, provide functional electrical stimulation of nerves, operate as glaucoma sensors, and monitor bladder and cranial pressure [3]. Electronic textiles (E-Tex)-based WBSNs for noninvasive health care monitoring will be the most... 

Hantzsche E, Matthes A, Nocke A, Cherif CH. Characteristics of carbon fiber based strain sensors for sfiucmral-health monitoring of textile-reinforced thermoplastic composites depending on the textile technological integration process. Sens Actuators A Phys 1 December 2013 A203 189-203. 

Huang, C.-T., Tang, C.-F., Lee, M.-C., Chang, S.-H., 2008b. Parametric design of yam-based piezoresistive sensors for smart textiles. Sensors and Actuators A (148), 10—15. 

---