Exploring distant destinations on Earth and in outer space such as the Antarctic and Mars is one of the most challenging and influential efforts of mankind that has greatly advanced science and technology. The ultraviolet (UV) irradiation at those remote locations, which is often accompanied by harsh environments, is usually strong due to the absence or depletion of ozone. Studies have shown that UV irradiation is one of the primary causes of skin cancer. Additionally, UV irradiation can degrade polymeric materials that are widely used in aerospace, automobile, marine industries,&nbsp;etc.&nbsp;For example, long-duration scientific balloons usually cruise in the stratosphere in or above the ozone layer, where the strong UV irradiation can damage the polymeric membranes and reduce the lifetime of balloons. In outer space such as low-earth orbits, UV irradiation is one of the most dangerous environmental threats to the health of astronauts and integrity of spacecraft materials such as Kapton, Kevlar, and carbon-fiber composite.&nbsp;Therefore, it is particularly important to monitor the UV irradiation in distant locations with harsh environments on Earth and in space for the safety of both human explorers and engineering materials.&nbsp;The results presented in the talk aim to address the above challenges through the introduction of routes to ultrathin, ultra-flexible nanocomposites based on zinc oxide (ZnO) nanoparticle and single-walled carbon nanotubes (SWNTs) for visible-blind UV sensing in mild and harsh environments. The ZnO/SWNT-based UV PDs achieve highly stable, repeatable, and high-quality visible-blind measurements of UV intensity in temperatures from -80oC to 100oC and atmospheric pressure as low as 6.7 kPa. This temperature range covers the typically harsh climates in widely explored destinations on Earth and in space such as the Antarctic, Arctic, low-earth orbits, and Mars. The atmospheric pressure of 6.7 kPa corresponds to an altitude of 18.7 km in Earth’s stratosphere, where scientific balloons often cruise.&nbsp;Moreover, the ZnO/SWNT-based PD can detect low UV light intensity that the commercial PD cannot reach. The ZnO/SWNT-based UV PDs can integrate with flexible near-field communication (NFC) circuits for wireless, battery-free data acquisition, potentially eliminating the cumbersome wires and reducing the weight and size.&nbsp;This wireless, battery-free optoelectronic system can also serve as a wearable platform for monitoring the UV exposure of human explorers.&nbsp;Additionally, the ultrathin, ultra-flexible ZnO/SWNT UV PDs realize non-invasive and conformal integration with other thin, intricate, flexible materials widely used in space and polar exploration, further demonstrating their potential in in-situ monitoring of UV exposure of unusual structures in demanding environments.

Ultra-Flexible Visible-Blind Optoelectronics for Wired and Wireless Ultraviolet Sensing in Harsh Environments

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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