Introduction

INTRODUCTION

With the growing population, the requirement for food and space has been on the rise. Emerging infectious diseases cause the loss of both human and animal lives as well as implicate a large cost to society. Factors such as climatic change, globalization, and urbanization are few reasons for increased infections and the emergence of new kinds of diseases. These pathogens are continuously mutating and raising much greater concerns. Few such deadly diseases are cholera, swim flu, covid, etc. There is huge research in the field of virology to investigate and study the disease to provide its cure, but even before we find the cure, to reduce the spread of diseases they must be sterilized and contained.

Disinfectants and Sterilization:

The knowledge of disinfectants and sterilization is the key component to control and block infections. Disinfectants cannot remove all micro-organism so using the right techniques to reduce the outbreak and spread of diseases plays a key role in hospitals and research facilities. Both disinfection and sterilization are used to remove pathogens. Disinfectants are used to remove pathogens but leave endospores. Leaving the endospores does not completely kill the pathogens so there is a chance that these endospores may further get back to life. Sterilization on the other hand destroys pathogens including endospores. Different techniques such as the use of halogens, oxygen, and radicals, etc are discussed in [1]. The killing of pathogens depends on different parameters such as the extent of time the pathogen is exposed to disinfectant, pH of disinfectant, temperature, etc.

Manual cleaning to reduce the spread of pathogens has high chances that the pathogens are not killed completely; it can be because of human error or not satisfying the exposure time and temperature on the area to be cleaned. As disinfectant usage will not completely remove pathogens, the use of UV light sterilization techniques is a proven method to kill pathogens. Usage of UV sterilization is safe and highly effective to kill pathogens.

Effect of UV light on humans and living organisms:

UV radiation is considered a carcinogen because of its property to initiate tumors and skin cancer and other environmentally influenced skin disorders. However, UV also can benefit human health by mediating the natural synthesis of vitamin D. Excessive exposure to UV carries health risks [5]. So, during sterilization, it’s most important that there is no human presence in the area. UV at 254 nm wavelength is effective in killing all the foodborne pathogens as the microorganism comes in different shapes so each organism has a different UV exposure time before they are destroyed [7].

Sterilization and its importance:

In the current situation, the pandemic has raised a global concern for sterilization. Sterilization and disinfection are basic components for the control of any infection. With the rise in COVID cases, the number of patients getting admitted into hospitals for treatment also increased. Besides COVID some patients are affected by various diseases undergoing surgical procedures, there is a high chance that the hospital environment is being packed with different pathogens which are to be contained for the betterment of hospital staff and patients. Moreover, there is a chance of transmission of infection from patient to patient; from a patient or to health care personnel, and vice versa; or from the environment to the patient due to improperly sterilized or disinfected equipment. Hence, medical personnel, laboratory people, and health care providers should have better knowledge regarding these techniques to prevent the spread of these pathogens [4]. The development of “no-touch” sterilization techniques, including the use of the mobile UV-light disinfection system would have a great impact in the field.

Motivation

The objective of the project is to make a low-cost autonomous UV sterilization robot. As it is medically proven that UV sterilization is powerful enough to kill contagious pathogens when exposed to UV light for ample amounts of time. Because of the latest advancements in the biotechnology field, pollution, and food habits, there are high chances of the rise of new contagious diseases. These diseases can be caused because of viruses or bacteria but there is a possibility that they can be killed using UV light. The present application is based on sterilizing the hospital wards autonomously without any human intervention.

ESP32 is a dual-core microcontroller with an onboard Wi-Fi and Bluetooth module enabling the user to communicate with the microcontroller wirelessly. ESP module enables the user to use it either as an access point or connect it to an access point (SoftAP mode). The dual-core microcontroller with FreeRTOS architecture makes it optimal to schedule multiple tasks parallelly. Initially, the project starts with understanding the basic components required such as the coding platform(ESP-IDF), simulation platform, and algorithm to be used. We started by simulating the algorithm designed and testing it under various scenarios and then optimizing the algorithm. Once we are confident enough about the performance of the algorithm the hardware is selected to develop the ESP32 firmware based on that. Next is the migration of autonomous algorithm logic to Embedded C and debugging the code. And finally testing all the systems together on real hardware.