Review on functionalized CNTs reinforced silicone rubber composites for potential wearable applications

Abstract

Wearable technology refers to the devices that are integrated with textiles, or implanted in the body or plants for smart monitoring. Hence, this wearable technology has attracted tremendous attention from researchers globally due to its smart functions to be useful for mankind. The key target of this review is to examine the potential of rubber composite materials for such wearable devices. The rubber composites reviewed explore silicone rubber as a rubber matrix (SR). Another objective includes the use of multi‐walled carbon nanotubes (MWCNTs) in pristine and functionalization forms explored as reinforcing fillers. Moreover, prospects of CNT including their structure, properties, and types are explored both in pristine and functionalized state are reviewed. Following this, the mechanical, and electrical, properties of such composites are reviewed. The reported results show that the reinforcing properties are strongly improved by adding functional groups to CNT in rubber composite. These improvements in reinforcing properties are assisted by the functional groups like carboxyl (OH), carbonyl (CO), epoxy, and alkoxy (CO) on the surface of filler are useful. They assist in improving the filler‐rubber compatibility thereby improving filler dispersion and thus finally mechanical and electrical properties. Following this, such improved properties are explored for specific real‐time wearable technologies. This real‐time monitoring includes nursing plant pulse growth monitoring, health monitoring, and humidity sensors. The review further proposes that the functionalized CNTs can be useful for obtaining robust real‐time strain‐sensing monitoring. Moreover, it assists in obtaining sharp response time, strain sensitivity, and good stretchability. Finally, the prospects and challenges are explored discussing the real‐time monitoring of these sensors.Highlights Configurations for nursing plant growth and other monitoring parameters are reviewed. The properties of pristine and functionalized carbon nanotubes reinforced silicone rubber for wearable technology were reviewed. The mechanical, and electrical aspects of functionalized carbon nanotubes were comparatively reviewed. Applications such as wearable strain sensors, humidity sensors, and wearable plant pulse monitoring sensors were reported.