Udayavni Special

Covid-19 survives on surfaces within thin films, according to researchers at IIT Bombay

PTI, Nov 25, 2020, 9:41 AM IST

Credit: iStock Photo

Mumbai: The Covid-19 virus survives on surfaces by clinging to thin liquid films, according to a study by researchers at IIT Bombay which provides insights into how the novel coronavirus sustains for hours or days on solid surfaces under ambient conditions.

The study, published in the journal Physics of Fluids, attributes the long survival time of the novel coronavirus on a surface to the slow evaporation of a thin nanometre liquid film remaining after the evaporation of the bulk droplet.

The ability to predict the survival of the novel coronavirus on different surfaces can help prevent and contain the spread of Covid-19, the researchers said.

While the typical respiratory droplets dry within seconds, the survival time of the SARS-CoV-2 virus on different surfaces within recent experiments has been found to be on the order of hours, they said.

This discrepancy suggests an order of magnitude difference in the time between droplet drying and the survival time of the Covid-19 virus on surfaces, according to the researchers.

The researchers described how a nanometres-thick liquid film clings to the surface, due to London-van der Waals forces, which allows the Covid-19 virus to survive for hours.

Van der Waals forces include attraction and repulsions between atoms, molecules, and surfaces, as well as other intermolecular forces.

“Our model for the thin film transport shows that survival or drying time of a thin liquid film on a surface is on the order of hours and days, similar to what has been observed in measurements of the virus titer,” said Amit Agrawal, professor at Indian Institute of Technology (IIT) Bombay.

“It captures the relatively longer survival time on plastic and glass compared to metals,” Agrawal said.

A titer is the lowest concentration of virus that still infects cells.

The nanometric film is assumed to be like a pancake deposited onto a surface. The researchers briefly examined changes in drying time as a function of contact angle and surface type.

“Our biggest surprise was that the drying time of this nanometric film is on the order of hours,” said Rajneesh Bhardwaj, a professor at IIT Bombay.

“It suggests the surface isn’t completely dry, and the slowly evaporating nanometric film is providing the medium required for the survival of the coronavirus,” Bhardwaj said.

Since a longer survival time of the virus corresponds to increased chances of being infected, the researchers said it is desirable to disinfect frequently touched surfaces, such as door handles or hand-held devices, and within hospitals and other areas prone to outbreaks.

“We also recommend heating surfaces, because even short duration high temperatures, at which the surface is at a higher temperature than the ambient, can help evaporate the nanometric film and destroy the virus,” Bhardwaj added.

Udayavani is now on Telegram. Click here to join our channel and stay updated with the latest news.

Top News

COVID-19: India records 44,230 fresh cases, 555 more fatalities

CBSE to announce class 12 results today

KS Eshwarappa ready to join new cabinet, unlike former CM Shettar

US to conduct rare 2nd lottery for H-1B visa applicants

Rahul Gandhi urges people in Kerala to adhere to Covid guidelines

Lovlina assures India of first boxing medal at Tokyo Olympics

Heinous: Monkeys poisoned, stuffed in gunny bags and beaten to death

Related Articles More

Twitter tests shopping in e-commerce move

Public advisory from ‘Vi’ against online & KYC frauds

Indian astronomers part of team spotting first short gamma-ray bursts from dying star

Microsoft along with SEEDS launch 2nd phase of AI model to predict heat waves risks in India

Facebook assembles team to build sci-fi-style ‘metaverse’


i was a Kannadiga in my previous birth | Happy Birthday Sonu Nigam | Udayavani

CM Basavaraj Bommai about Cabinet Expansion



Vandana Rai Karkala and her innovative teachings

Latest Additions

BSY to visit his supporter’s bereaved family

SC to hear next week plea of senior journalist N Ram on Pegasus issue

Govt looking for prospects about green hydrogen as potential transport fuel, says Min Gadkari

COVID-19: India records 44,230 fresh cases, 555 more fatalities

DK dist child helpline receives record 113 calls in July

Thanks for visiting Udayavani

You seem to have an Ad Blocker on.
To continue reading, please turn it off or whitelist Udayavani.