Sorting out smart trash

The term "smart trash" is neither an oxymoron, like "military intelligence" or "promising semiconductor stock," nor a reference to a Ph.D. living in a trailer park. It's a term for giving our waste stream enough intelligence to identify itself, assist in its own sorting and recycling process, and prevent the wrong stuff from ending up somewhere it can do harm.

This idea of a self-sorting waste stream, the brainchild of Valerie Thomas of Princeton University, may represent an important opportunity for the electronics community to significantly lower the cost of recycling its own products as well as many other by-products of our industrial society.

Using networks that read low-cost bar code labels, RFID tags and other simple tagging technologies, Thomas hopes to improve the economics of product recycling and turn our one-way waste stream into a two-way, closed-system supply chain.

In a retail-oriented smart-trash system, consumers might return batteries, containers and other items to stores at the end of their life to be "unsold." A scanner in the checkout line or an "unvending" machine would read the tag on each item and then issue a refund in the form of cash, coupons or store credit. That would provide consumers with a real incentive to keep the stuff out of the regular trash.

From there, it's easy to imagine a day when most electronic products contain enough information about themselves to be quickly sorted, dismantled and recycled. Thomas is in a project to apply smart-trash technology to the problem of recycling cellphones in Europe. In a joint effort with Motorola, her team is developing a system that reads the manufacturers' bar codes already on a cellphone to determine its make and model as well as the proper disassembly and salvage procedures. This is expected to significantly cut the labor costs associated with the mandatory electronics-recycling programs being phased in throughout Europe.

Soon, it should be possible to apply them to computers, radios, TVs and most other consumer electronics, making it much more cost-effective to "mine the scrap heap" for materials, and perhaps components, to make the next generation of products. Besides making electronics recycling more cost-effective, smart trash may offer some big opportunities to develop and sell the "smart trash cans," "smart garbage trucks" and "smart conveyor belts" that will form the heart of a waste-handling system that keeps 80-90 percent of the stuff it sees out of the landfill or incinerator.

I think smart trash will play an important role in building a greener future. I also smile every time I imagine a smart recycling bin reading the smart labels on your bottle or can and letting you know if you're tossing it in the right hole or not.

- Lee Goldberg

EE Times