New cheap, organic molecule can aid digital storage and energy harvesting

25 Jan 2013

An organic, flexible, carbon-based molecule has been discovered by a team comprised of researchers from the University of Washington and China’s Southeast University. It has properties that are highly suited for use in memory, sensors and low-cost energy storage.  

The molecule itself is made from bromine, an element present in sea salt. The bromine is then mixed with carbon, hydrogen and nitrogen before being dissolved in water, which is then evaporated in order to grow the crystal. The full name of the molecule is diisopropylammonium bromide and it is flexible due to pivoting chemical bonds, providing another favorable characteristic over the brittle materials used today. 

Importantly, diisopropylammonium bromide is ferroelectric, meaning one side of the molecule is positively charged and the other is negatively charged. In today’s market, synthetic ferroelectrics are used in displays, sensors and memory chips.  

The performance of ferroelectric materials is typically measured against barium titanate, a longstanding contender for industrial applications. When pitted against the newly discovered molecule, it was found that diisopropylammonium bromide performed very favorably, scoring 23 on a measure of its natural polarization, compared to barium titanate’s 26. This makes it the best-performing organic ferroelectric discovered so far.  

In addition, the molecule retains its properties at high temperatures, and is a good piezoelectric, meaning it is efficient at converting movement into electricity, which is useful in sensors. It can also store energy far better than other organic ferroelectrics, with its dielectric constant scoring ten times higher. 

These remarkable properties mean it will hopefully contribute to developing cheaper ways of storing digital information, as well as finding applications in medical sensors and energy harvesting. Further research is currently being done to fully understand its combined electric and mechanical properties.    

“This molecule is quite remarkable, with some of the key properties that are comparable with the most popular inorganic crystals,” said Jiangyu Li, a University of Washington associate professor of mechanical engineering who was heavily involved with the research. 


Further information

Organic ferroelectric molecule shows promise for memory chips