Smart Fabrics
December 6, 2012, Printed Electronics USA, Santa Clara, CA—Jamshid Avloni from eeonyx talked about smart fabrics and their applications. They have to tailor the electrical and mechanical properties of the components to work in the applications.
One application is resistive fabric heaters. Unlike electric blankets with a heater wire snaking around the blanket and causing hot spots, these fabrics are almost isothermal. After they got the heaters working, they are starting on integrating sensors into the fabrics. The idea is to make surface-attached sensors that retain the properties of the original fabric while adding new capabilities.
Some of the sensors include pressure, impact, strain, and bending. Possible applications include exoskeletons and bed pressure sensors to alleviate or eliminate bed sores in hospitals. The most important consideration is to have the electronics merged into the fabric surface to keep from having hard lumps for the sensors.
The engineered materials use a 3-layer construction of orthogonal conductors for the basic wiring. For the sensors, piezo materials are placed in the junctions to provide wide area, high resolution sensing capabilities. Touch and gesture functions are available from a pad-type device.
When the materials are made into a glove, the sensors can output bend by recognizing the large number of pressure points that relate to finger and palm locations and compression information from the sensor output voltages. Impact sensors can determine location and force of an impact, possibly useful for areas like concussion studies in contact sports.
They are also working on combining the heaters and sensors to make closed loop temperature controllers. These items might be useful in neonatal care units to keep the babies at a comfortable temperature with better control than is available in an incubator or other device.
The meta-materials have another interesting characteristic, they absorb radio waves. The conductive portions capture the radar signals and the resistive portions convert the incoming energy into heat, leaving little to be reflected back to the receiver.
