1.1 Introduction
An automatic liquid dispenser vending machine is an electronically controlled device designed to release a measured quantity of liquid to a user without requiring continuous manual operation. The system normally combines a microcontroller, sensors, liquid storage container, pump or valve, power supply, and a dispensing outlet. Depending on the design, the user selects or activates the required quantity, while the control unit processes the input and operates the dispensing mechanism. Banani et al. (2026) explained that an automatic dispensing system is capable of using a microcontroller, flow sensor, pump, and valve to regulate and measure the quantity of liquid released.
Automatic dispensing technology is increasingly associated with convenience, controlled quantity, reduced human effort, and improved operational consistency. Traditional liquid dispensing often requires a person to open a tap, operate a pump, or manually measure the required quantity. Such processes are potentially affected by inaccurate measurement, spillage, unnecessary contact, and delays.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the aim and objectives of the study. Others are significance of the study, scope of work, limitation of the study and definition of terms.
1.2 Background of Study
Historically, vending machines dates back several centuries. One of the earliest recorded vending concepts is associated with Heron of Alexandria, who described a device that released a measured quantity of liquid after a coin was inserted. The principle involved controlling the flow of liquid so that the user received a predetermined quantity. The modern vending machine developed much later through mechanical engineering. According to Segrave (2002), vending machines became more prominent during the nineteenth century as inventors developed mechanisms for releasing products after a user performed a particular action. In the 1880s, Percival Everitt developed a machine for dispensing postcards, helping to establish the commercial vending-machine concept.
According to Segrave (2002), vending machines developed from simple mechanical devices into systems designed to provide goods to users with limited direct assistance from an operator. The basic idea behind vending technology is to allow a user to obtain a product after fulfilling a specified condition, such as inserting money, selecting an option, or activating a control. Similarly, the development of automatic vending machines was closely connected with improvements in mechanical engineering and control mechanisms. Historical records indicate that modern coin-operated vending machines became prominent in London during the 1880s, with Percival Everitt associated with an 1883 machine for dispensing postcards. The development showed that a mechanical system was capable of controlling access to a product and releasing it after a defined user action. Over time, vending machines expanded from simple mechanical devices to more sophisticated systems involving electrical and electronic controls.
Segrave (2002) stated that, vending machines gradually became useful for dispensing different products, including food, drinks, tobacco products, newspapers, and other consumer items. The main attraction was convenience because users were able to obtain products without direct interaction with a shop attendant. This principle remains relevant to modern vending technology, although present-day machines frequently use electronic sensors, microcontrollers, displays, motors, pumps, and digital payment systems. Furthermore, the development of electronics introduced a major change in the way dispensing machines operate. Instead of depending entirely on mechanical levers and coin mechanisms, modern systems are capable of receiving electronic inputs and processing them through programmed control units.
Erham (2019), microcontrollers and sensors are useful in automatic dispenser systems because they provide a means of detecting conditions and controlling the dispensing process. In a liquid dispenser, a sensor is capable of detecting the position of a cup or container, while the controller processes the information and activates the relevant output device. The pump, motor, or solenoid valve then controls the movement of the liquid. In the same vein, Hakim (2023) stated that an Arduino-based automatic dispenser is capable of using an ultrasonic sensor as an input device and a relay to control a water pump. The arrangement demonstrates how relatively simple electronic components can be combined to create an automated liquid dispensing system. The approach is particularly relevant to prototype development because Arduino-based controllers are suitable for testing programmed control functions and connecting different electronic components. This study is set against the backdrop of the growing application of automation, sensor technology, microcontrollers, and controlled liquid dispensing systems in solving simple everyday operational problems.
1.3 Statement of Problems
Investigation revealed that conventional liquid dispensing systems often require users to operate taps, buttons, or pumps manually before liquid is released. On the other hand, manual operation also provides limited control over the dispensing process, particularly where a specific quantity is required.
Additionally, existing systems are potentially affected by liquid overflow and inconsistent quantity because the user is responsible for stopping the flow at the appropriate time. Furthermore, frequent physical contact with dispensing components is potentially undesirable in shared environments.
Furthermore, the absence of a simple and affordable automated system creates a need for a dispenser that is capable of detecting a container, controlling liquid flow, and stopping the operation at the required point. It is against this backdrop that this study seeks to design and construct an automatic liquid dispenser vending machine.
1.4 Purpose of Study
The purpose of this study is to design and construct an automatic liquid dispenser vending machine that is capable of detecting user input, controlling liquid flow, and dispensing a predetermined quantity with minimal manual intervention.
1.5 Aim and Objectives of Study
The aim of this study is to design and construct an automatic liquid dispenser vending machine for controlled, convenient, and efficient liquid dispensing.
The specific objectives of this research are to:
- Design an automatic liquid dispensing system using appropriate electronic and mechanical components.
- Develop a sensor-based control mechanism for detecting the user or dispensing container.
- Construct a pumping or valve mechanism for controlling liquid flow.
- Program the control unit to regulate the dispensing process according to predetermined conditions.
- Test the performance of the developed prototype in terms of operation, response, accuracy, and reliability.
1.6 Significance of Study
It is believed that at the completion of the study, the project will provide a practical demonstration of how automation is applied to liquid dispensing. The prototype will also show the relationship between sensors, controllers, and actuators.
Furthermore, the project will provide students with practical experience in designing and connecting electronic components for an automated system. Also, the project will provide a basic model for businesses interested in controlled and automated liquid dispensing applications.
Lastly, the project will provide a dispensing method that will reduce the need for repeated manual operation during the dispensing process.
1.7 Scope and Limitations of the Study
The scope covers the design, component selection, programming, construction, integration, and testing of an automatic liquid dispensing prototype at the University of Benin, Edo State. The system focuses on detecting the dispensing condition and controlling liquid flow through an electronic controller and actuator.
The study is limited by the type of components available for the prototype, the selected liquid, available power supply, testing environment, and the capacity of the storage container. The project does not cover large-scale commercial vending operations, advanced cashless payment systems, cloud-based monitoring, or industrial-scale liquid production.
1.8 Definition of Terms
Automatic:
Automatic refers to an operation performed by a machine according to programmed or predetermined instructions without continuous human control. In this project, automatic operation means that the dispensing process is activated after the system detects the required input.
Automatic Liquid Dispenser:
An automatic liquid dispenser is a device that releases liquid through an electronically or mechanically controlled mechanism.
Vending Machine:
A vending machine is a self-service machine designed to deliver a product after a user performs a required action, such as making a payment or selecting an option.
Liquid:
Liquid is a state of matter that has a definite volume but takes the shape of its container. In this project, liquid refers to the substance stored and released through the dispensing mechanism.
Microcontroller:
A microcontroller is a small programmable electronic device used to receive inputs, process instructions, and control outputs. In the proposed system, the microcontroller serves as the main control unit.
Sensor:
A sensor is an electronic component that detects a physical condition and produces a signal for processing. An ultrasonic sensor, for example, is capable of detecting the presence or distance of an object and sending the information to a controller.
Ultrasonic Sensor:
An ultrasonic sensor is a device that uses sound waves above the normal range of human hearing to detect the distance or presence of an object.
Water Pump:
A water pump is an electromechanical device used to move liquid from one location to another. In an automatic dispenser, the pump is activated by the controller to move liquid from the storage container toward the outlet.
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