Self-Powered Robotic Sensor for Remote and Real-Time Monitoring of Heavy Metal Ions

Abstract

In the recent years, heavy metal pollution has tremendously increased worldwide due to natural as well as anthropogenic reasons. Heavy metals accumulate in the human body through drinking water and food, ultimately causing irreversible damage to the body. For most of the heavy metals, the World Health Organization (WHO) has set permissible limits from 0.003-3 ppm in drinking water, above which it is contaminated. In addition, chemical threats remain a major global concern for sampling and sensing factors in unsafe environments. Therefore, robotic hand-based chemical sensing platforms that can monitor hazardous pollutants in the real environment are essential. Although robotic hand-based chemical sensors show great potential to substantially prevent humans from chemical threats in the environment, applications are often limited by the requirement of high-power consumption. In this study, we have fabricated a self-powered triboelectric nanosensor, which is integrated with a robot platform with wireless transmission capability, to detect heavy metal ions in the environment through a rapid onsite detection mechanism. In this regard, a copper electrode modified by an ion selective membrane (ISM) is used as a solid triboelectric material and is integrated with a robotic hand. Since the ionophore selectively binds to the corresponding ions, the solid-liquid TENS could detect Cr6+, Pb2+, and As3+ ions at a wide range of concentrations by the periodic contact and separate motion of the sensor probe to lead (Pb2+), arsenic (As3+) and chromium (Cr6+) solutions. This realization of direct integration of self-powered sensors with robotics provides low-cost and automated chemical sensing mechanisms. It can be applied to various environments for on-site detection of hazardous analytes and security. Finally, a real time remote monitoring system allows the presentation of the environmental monitoring data on mobile devices and enables remote real-time monitoring of the hazardous pollutants.