  Monitoring structural integrity during and after extreme events such as an
earthquake or a tsunami is a mundane yet important task that still awaits a
workable solution. Currently available stress sensors are not sufficiently
robust and are affected by humidity. Insufficient information about crack
formation preceding structural failure increases risk during rescue operations
significantly. Designing durable stress sensors that are not affected by harsh
and changing environment and do not fail under catastrophic conditions is a
fundamental challenge. To address this problem, we developed a stress sensor
based on creased single-walled carbon nanotubes (SWCNTs) encapsulated in a
non-fluorinated superhydrophobic coating. The creased SWCNT film was fabricated
and integrated in polydimethylsiloxane (PDMS) to provide a highly linear
response under elastic deformation. The non-fluorinated water-repellent coating
was fabricated by spray-coating the film with nanosilica particles, providing
water resistance during elastic deformation. The compact design and superior
water resistance of the sensor, along with its appealing linearity and large
stretchability, demonstrates the scalability of this approach for fabricating
efficient strain sensors for applications in infrastructure and robotic safety
management as well as advanced wearable sensors.
