Advanced Smart Waste Segregation System

What it does

Our smart waste segregation system uses sensors and a rotating chute to automatically sort waste into metal, glass, plastic, and paper bins. It addresses poor recycling habits by reducing contamination and making waste separation easy and touch-free.

Your inspiration

The idea stemmed from observing how public and campus bins often go unused or misused as people tend to throw everything into the general bin, ignoring the tri-coloured recycling bins due to inconvenience or confusion. We realized that proper waste segregation is critical to Malaysia’s recycling efforts yet current solutions rely heavily on manual sorting. Inspired by the potential of sensor technology and smart automation, we envisioned a hands-free system that could handle sorting with minimal user effort. This would encourage proper disposal behavior while reducing contamination in recyclable waste streams.

How it works

Our smart waste segregation bin uses sensors and motors to automatically identify and sort household waste into four categories: metal, glass, plastic, and paper. When a person approaches, a motion sensor (PIR) activates the system. The waste is placed into a central chute, where a set of sensors detects the material type—an inductive sensor for metals, a capacitive sensor for glass, and an infrared sensor to distinguish between plastic and paper. Once identified, a motor-driven rotating bin selector aligns the chute with the correct waste bin using a gear mechanism. Then, a servo motor opens a flap to release the waste into the selected bin. After sorting, the selector returns to its default position. The system is powered by an AC to DC converter and managed by an Arduino microcontroller programmed to control the logic flow. This automated process ensures accurate sorting, reduces manual handling and improves recycling rates.

Design process

The design process began with identifying a common issue on campus: users often ignored the tri-coloured recycling bins and threw all waste into a single bin, leading to contamination. From there, we conceptualized a smart bin that could automate the sorting process. We developed three initial concept designs and selected the best based on functionality, cost, and user-friendliness. CAD models were created to visualize the chosen concept, and structural simulations were conducted to validate its mechanical strength. Due to material and fabrication limitations, we scaled the prototype to 60% size. We repurposed a 145L HDPE water drum as the main bin body and fabricated internal structures using laser-cut plywood and acrylic frames. The rotating bin selector and gears were 3D-printed using PLA. Sensors were tested for compatibility and positioned in the chute to ensure close contact with waste. We iteratively refined the circuit and Arduino code during prototyping to reduce sorting delays and improve accuracy. The mechanical assembly was tested for movement precision, and toggle latches were added for easy bin removal. This prototype balances cost, modularity, and functionality, demonstrating the feasibility of a fully automated, user-friendly sorting system.

How it is different

Unlike conventional smart bins that often rely on camera-based AI recognition or static multi-compartment layouts, our system uses a rotating bin selector mechanism controlled by a gear-driven stepper motor for precise and efficient sorting. Instead of requiring the user to choose the correct bin, the system automates classification using a multi-sensor array—inductive, capacitive, and infrared sensors—offering a cost-effective alternative to complex vision systems. The modular design allows each bin to be removed independently for easy cleaning, and toggle-latched flaps keep the bins securely in place. Our approach prioritizes affordability, hygiene, and compact integration, making it ideal for high-traffic public spaces like universities. With minimal user interaction and low power consumption, this solution bridges the gap between manual bins and expensive industrial smart sorters, especially for developing regions like Malaysia.

Future plans

Our next steps include improving the sensor accuracy and refining the mechanical design for smoother operation. We aim to develop a fully enclosed, weather-resistant version suitable for outdoor use. After further testing and stakeholder feedback, we plan to explore local manufacturing partnerships and pilot deployments around campus. Ultimately, we hope to scale this solution across universities and public spaces in Malaysia, contributing to better recycling habits, reducing landfill waste, and supporting national sustainability goals.

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