Design and Optimization of a Low-Cost DC Electric Motor for IoT-Based Smart Device Applications

The rapid development of Internet of Things (IoT) technologies has intensified the need for compact, cost-effective actuators that can be seamlessly integrated into smart devices such as home automation systems and portable robotics. This study presents the design, construction, and optimization of a low-cost direct current (DC) electric motor using readily available materials, including copper wire, an iron core, and neodymium magnets. A series of experiments were conducted to evaluate the influence of coil turns, magnet strength, input voltage, and pulse-width modulation (PWM) duty cycles on torque, rotational speed, and efficiency. Results demonstrated that a configuration with a 100-turn coil, a 0.4 Tesla magnet, and a 9 V power input achieved a rotational speed of 160 RPM with an efficiency of 34%, confirming suitability for low-power IoT devices. Finite Element Analysis (FEA) was employed to validate and refine the experimental design, showing a 20% improvement in magnetic flux density and a close correlation with measured torque values. Furthermore, the motor was integrated with an ESP32 microcontroller, enabling precise speed regulation and remote operation via Wi-Fi and MQTT protocols, as demonstrated in a prototype smart fan application. With a total manufacturing cost of under $5, the proposed motor design offers a scalable and affordable solution for resource-constrained environments, addressing barriers to widespread IoT adoption in developing regions. The findings highlight the potential of combining simple construction methods with digital control and simulation tools to create efficient, accessible, and IoT-compatible actuators that support ongoing advancements in smart device technology.