A team of engineers based at the University of Utah has created components of LEDs (Light Emitting Diodes) out of waste from food and beverage.
Bread, tortillas and soda were treated with high temperature and pressure in specific solvents to form ‘quantum dots’, crystalline structures 20 nanometres in size which have luminescent properties.
Using food and beverage waste allows quantum dots to be carbon-based, which differs from traditional selenium or cadmium based quantum dots.
LEDs are very widely used in appliances such as television screens and lightings.
Professors Prashant Sarswat and Michael Free have published the work in the journal Physical Chemistry Chemical Physics.
Image credit: Tom Raftery / Flickr
This development has three major benefits:
- Professor Michael Free explains that “[quantum dots] derived from food and beverage waste are not based on common toxic elements…which makes their processing and disposal more environmentally friendly”.
- The use of surplus food and beverage has the potential to reduce the massive amounts of waste.
- The high costs of rare and expensive elements in LEDs are replaced by starting products that are essentially free (although this could change).
This follows a trend of engineers turning to waste to develop high-tech components, such as using old tyres to create supercapacitors. Currently, such innovations are stuck in the laboratory, but they hold great potential, especially when compounded by resource scarcity and environmental concerns.
One notable exception is the huge interest and projected $390 million industry generated by Graphene, the single-layer carbon wonder material.
Can the creation of LEDs out of waste food and beverage be scaled up to market level? And how might that affect the value placed on discards?
Professor Sarswat: "The ultimate goal is to do this on a mass scale and to use these LEDs in everyday devices. To successfully make use of waste that already exists, that's the end goal".
Will our future homes be lit by leftovers?
Science Daily (October 13, 2015) Light emitting diodes from food and waste created
Physical Chemistry Chemical Physics (October 1, 2015) Light emitting diodes based on carbon dots derived from food, beverage, and combustion wastes