One of the main reasons for the low recycling rate of plastics in Singapore is contamination of recyclable plastics with other materials such as food residue and mixing of different types of plastics. Even with improved solutions such as the Recycle Right bins that have been deployed in NUS, the contamination rate may be as high as 27% which exceeds the maximum allowable level of 5% to 10%. Moreover, there is a lack of incentive for consumers to recycle and to do so properly.

To address this problem, a Sorting Mechanical Automatic Recycling Tech (SMART) Bin was designed in this project. The bin helps to passively educate users to recycle polyethylene terephthalate (PET) bottles correctly while actively sorting waste discarded into the bin. It employs computer vision with weight detection to detect empty PET bottles which can be recycled versus other types of waste which must be separated from the recyclable PET bottles. Using a novel rotation mechanism, it can efficiently process and classify each PET bottle.