Investigating the Feasibility of a Conductive Textile Structure to Indicate Pre-tensioning of Seat-belts

摘要

Child safety restraints and seat belts have been legally mandated in many countries as they reduce the risk of death or serious injury in a vehicle crash. However, recent studies demonstrate that pretightening or over-tightening of the safety restraints results in major physiological discomfort and severe injuries to the wearer. This occurs due to improper positioning of the belt as well as uneven load distribution, and a toddler or child may not be able to acknowledge this fact, thus highlighting the contemporary necessity for a system to indicate such a phenomenon. Therefore, the feasibility of a textile based system that incorporates the principle of a strain indicator, where the imposed strain on the safety harness would be measured relative to the surface resistivity of the developed conductive fabric has been investigated in this research. Cotton fabric was polymerized in situ with Polyaniline, where the aniline/HCl solution was polymerized by drop casting an ammonium persulphate/HCl solution to impart conductivity to the textile structure, by grafting conductive nano fibers on the surface of the cotton. An Arduino Uno interface was used to plot the variations of the voltage level in response to the strain imposed at a baud rate of 9600, with an LED indicator triggered at variations of the pre calibrated base voltage level. The study concluded that a 16.85% variation of the surface conductivity was achieved per unit elongation of the fabric structure, which is sufficient to establish a safety interval, for the tensile strain of the seat-belt.