Rubber-based strain sensor fabricated using photolithography for intelligent tires

From a traffic safety point-of-view, there is an urgent need for intelligent tires equipped with strain sensors as a warning system for road conditions and for optimized braking control on poor road surfaces. However, since a conventional foil strain gage has high stiffness, it causes the analyzed region to behave unnaturally. The present study proposes a novel rubber-based strain sensor fabricated using photolithography. The rubber base has the same mechanical properties as the tire surface; thereby the sensor does not interfere with the tire deformation and can accurately monitor the behavior of the tire. This investigation details the design and manufacture of the rubber-based sensor. For verification, the sensor was attached to a beam specimen and found to have a fatigue life of over 106 and a measurable strain range up to 14%. The sensor was applied to a commercially available automobile tire and found to successfully measure the strain of the tire.