UM scientist takes on dengue with human-scented street light

Dr Chong Wen Tong and his team of UM researchers have designed a street light that emits human scent to attract mosquitoes. – The Malaysian Insider pic by Fiqah Mokhtar, February 28, 2016.Alarmed by the record outbreak of dengue cases in Malaysia over the last two years, University Malaya (UM) researchers, led by mechanical engineering department associate professor Dr Chong Wen Tong, have invented a street light that traps mosquitoes with fake human scent.

Work on the invention, which draws mosquitoes to the light and traps them, began three years ago and the first prototype was ready some 20 months ago, said Chong.

The “Eco-Greenergy Self-Sustained Outdoor Lighting with Mosquito Trap and Flood Emergency Warning Transmission System”, uses a special chemical that replicates the smell of humans.

“The mosquito trap works to draw mosquitoes that like UV (ultraviolet) light. Mosquitoes are attracted to light and heat like the temperature of the human body. So we coated the light with the special chemical.

“When UV light interacts with the special chemical, it will release a small amount of CO2 to lure mosquitoes. It creates the scent that the human body releases when breathing,” Chong told The Malaysian Insider.

UM’s medical faculty contributed to the project by developing chemicals to replicate the human scent.

Chong said he could not reveal more about the chemical but added that it was possible to synthetically create the smell of human sweat, which attracted mosquitoes, too.

However, that also depended on the type of mosquitoes, he said.

“We are still working the the Parasitology Department professor to assess the effectiveness of the scent. For the time being, it is most effective on the Aedes mosquito,” he said, referring to the known carrier of the dengue virus.

The street light traps mosquitoes with chemicals that replicates human scent. – Pic courtesy of Dr Chong Wen Tong, February 28, 2016.Chong and the invention were featured in the UK paper The Guardian last month, at a time when cases of the mosquito-borne disease have increased in Malaysia despite years of hygiene and cleanliness campaigns.

Last year saw an 11.2% increase in dengue cases nationwide compared to the previous year, with 120,836 against 108,698 cases in 2014.

Since the start of the year until February 13, there were 19,733 cases compared to 18,351 last year over the same period.

The Health Ministry has warned that hot weather can spur Aedes mosquito activity and that the El Nino phenomenon this year may increase dengue cases by 50%.

One plus point for Chong's LED street lamp is its use of clean energy. Unlike regular street lights, which need underground wiring, the light can be powered by wind and solar energy.

“Our light is a stand alone, using wind and solar power,” Chong said, pointing to the battery storage located in the upper part of the light post that freed up space for a mosquito trap.

And since the wiring is at the top part of the light, it is suitable for flood-prone areas.

But during floods, he said power supply must be turned off for safety reasons.

In such situations, the light must generate enough electricity using wind and solar power to work.

“The battery or storage, wiring system and controller are placed near the top portion and can still function even when the flood level is 4m, depending on how high the post is.

"A sensor can be integrated and hidden inside the hollow pole (to prevent vandalism) to sense the flood water level and transmit warning signal to search and rescue centres.

"The excess power can also be used to power the mosquito trap that can be integrated to the pole.”

The light is undergoing pilot testing at UM's main campus in Kuala Lumpur and all parts of the street light are ready for commercialisation except the mosquito trap, which will be ready in six months' time.

The project won top prize at the International Conference and Exposition on Inventions by Institutions of Higher Learning and the gold medal, making one of UM's highest achievements.

Chong said the most important thing for any project was its benefits to the people and society

“For example, everyone is worried about dengue and the Zika virus. Now we have created a mosquito-trapping street light.

“Even if it does not solve the problem 100%, at least it can have a 30% to 50% impact. That can make a huge difference to people.”

Money for the project came from UM’s research fund, the Higher Education Ministry and the Prototype Research Grant Scheme. – February 28, 2016.