Design, Development and Engineering Evaluation of An Automated Disinfectant Tunnel Developed At the National Space Research And Development Agency (NASRDA) During The Covid-19 Pandemic

The COVID-19 pandemic created an urgent need for innovative technological solutions capable of supporting hygiene, environmental control and infection-control activities in public and institutional environments. In response to this challenge, an automated disinfectant tunnel was designed and developed at the National Space Research and Development Agency (NASRDA), Nigeria. The system was conceived as a contactless, sensor-controlled liquid-dispensing structure through which an individual could pass while a disinfectant solution was automatically delivered through strategically positioned spray nozzles. This study presents the design, development and engineering evaluation of the prototype, with particular emphasis on its component architecture, sensing mechanism, control strategy, fluid-delivery arrangement and subsystem integration. The developed prototype comprised a 220 V electric pump, storage tank, spray nozzles, pipes, T-connectors, passive infrared (PIR) motion sensor, ultrasonic sensor, Arduino Uno microcontroller, relay, temperature indicator, breadboard and electrical wiring. The Arduino Uno served as the principal control unit, receiving signals from the sensing devices and processing them according to the programmed control logic. The PIR sensor provided motion detection, while the ultrasonic sensor provided distance-based presence detection. When the programmed detection condition was satisfied, the Arduino generated a control signal that activated the relay. The relay subsequently switched the electrical supply to the 220 V pump, causing liquid to be withdrawn from the storage tank and conveyed through the pipe network to the spray nozzles. The engineering assessment demonstrates the integration of embedded control, sensing technology, electromechanical switching and fluid-delivery components in the rapid development of an indigenous technological response during an emergency situation. The prototype also demonstrates the potential of low-cost microcontroller-based systems for developing automated dispensing and environmental-control technologies. The principal contribution of this study is the systematic documentation of the NASRDA prototype, including its design architecture, component functions, operating principle, control strategy and engineering considerations. The study does not claim clinical efficacy or establish that human spraying prevents SARS-CoV-2 transmission; rather, it documents the engineering development and lessons arising from the prototype.