Students develop self-sanitizing door handle

Humza

TechSpot Staff
Staff member

Sum Ming Wong and Kin Pong Li have invented a door handle that people might actually want to use, considering that it employs light-sterilization that's deemed to be a better alternative than most current solutions.

The students were motivated by an outbreak of the severe acute respiratory syndrome (SARS) in the early 2000s, which was due to a virus spread by small mammals in China. The epidemic sickened over 8,000 people in 2003 and claimed the lives of 774, mostly in China and Hong Kong, according to the World Health Organization.

To reduce the spread of such viruses, Wong and Li developed the "self-sanitizing door handle" out of a glass tube in the middle and two aluminum caps at both ends. The handle is covered by a special photocatalytic coating made from titanium dioxide and is powered by an internal generator that converts kinetic energy (door movement) into light energy to continuously power the UV light.

"We knew that many infections can spread out by contact, for example, SARS, MERS, Foot and Mouth Disease and Candida auris," said the students, and since public bathroom door handles are usually the hotspots for bacteria, they believe their design to be durable and effective as opposed to chemical cleaning materials that get wiped off easily and are harmful to the human body.

In lab tests, the UV door handle was able to destroy around 99.8 percent of microbes and is also one of the winning entries in the 2019 James Dyson Awards, the UK-based competition that recognizes and celebrates the world's best in student design and engineering.

Permalink to story.

 

stewi0001

TS Evangelist
Platinum
Overall I like the idea, but what about people touching it? UV-C is harmful to the human body too. There might be something I'm missing here.
 

Uncle Al

TS Evangelist
Good observation and even better answer! Considering the type and amount of bacteria transmitted from "public surfaces" the slight exposure from UV through contact is negligible. There are probably more than a few other applications to this that would be beneficial .... except for toilet seats ..... I'm going to be there more than a few minutes and certainly don't want my better half to notice I have a bright red ring around the bottom! There is already too much laughing when I disrobe .........
 

stewi0001

TS Evangelist
Platinum
The amount you'd be exposed to simply by holding a door handle for 2-3 seconds would be minimal. You're also exposed to UV light from the sun constantly - it's only after several minutes that it starts to "burn" you.
Correct. I am rusty on my UV knowledge but I do recall that there are different UV classifications and the one that is used for sanitation is UV-C because it breaks apart the DNA, which for a small organism like a virus, bacteria, etc means death. Basically, I need to refresh myself on the subject since I cannot remember how much UV-C we get from the sun and etc.

I guess what I am more concerned about is if it is a door you frequently open. But as I stated, I need to refresh myself on the topic.
 

wiyosaya

TS Evangelist
The surfaces, while problematic, are hardly as bad as jet hand driers in public bathrooms. https://www.webmd.com/a-to-z-guides/news/20141121/restroom-hand-dryers-spread-more-germs-than-paper-towels-study-finds
Personally, I use paper towels whenever I can.

Why not just use brass?

The surfaces of copper and its alloys, such as brass and bronze, are antimicrobial.
https://en.wikipedia.org/wiki/Antimicrobial_copper-alloy_touch_surfaces#Clinical_trials
That's too simple. It must be complicated for it to be effective. ;) :laughing:
 

Evernessince

地獄らしい人間動物園
This seems like a bad invention to incubate poor hygiene. A lower wattage UV light won't kill all bacteria (heck there is some bacteria that can survive powerful UV exposure). In addition, because UV is a light type of radiation, it mostly impacts the surface of whatever is facing it. Light does not penetrate deeply into matter like Microwaves, meaning that any "material" left on the handle will block it from doing it's job.
 

Markoni35

TS Maniac
Handle covered with titanium dioxide? Hmmm....

Isn't it interesting that sunscreen is full of titanium dioxide, the same ingredient that kills bacteria and causes destruction of cells in general? In fact, TiO2 is now poisoning marine life on some beaches, because people use sunscreen, go swimming, and TiO2 is washed into the sea.

So, TiO2 is dangerous for bacteria and sea organisms, and cells in vitro, but somehow is "safe" for skin cells? Of course it's not. It kills living things. Not just bacteria, not just sea life, but your skin too.

Not to mention that handle emits UV radiation, which is also harmful for your eyes if you're looking directly at it (which no doubt children will do, since the handle looks very cool). From now on kids should wear sunglasses when going to the toilet.
 

jpuroila

TS Booster
So, TiO2 is dangerous for bacteria and sea organisms, and cells in vitro, but somehow is "safe" for skin cells? Of course it's not. It kills living things. Not just bacteria, not just sea life, but your skin too.
The entire reason for having specialized skin cells is that they die so the rest of your cells stay protected. Skin cells dying is not a problem(unless it happens at a sufficiently massive scale, obviously). It's only a problem if they DON'T die and develop into a cancer instead(which can happen in case of UV-light, for instance).
 
  • Like
Reactions: TempleOrion

TempleOrion

TS Enthusiast
Why not just use brass?

The surfaces of copper and its alloys, such as brass and bronze, are antimicrobial.
https://en.wikipedia.org/wiki/Antimicrobial_copper-alloy_touch_surfaces#Clinical_trials
It'll all come down to cost I suppose, and commodity prices do oscillate quite violently sometimes. I know local hospitals around here are replacing pushplates and door handles with copper ones.

Wish the gyms would do so too (or use this invention instead, if that looks cooler LOL)...
 

Yynxs

TS Addict
I actually chuckled here because I remember copper door knobs and push plates on doors. They were taken out because they were too expensive to keep shiny as cost of unskilled labor rose.
Now here are young people espousing their virtues. I wonder if they know how difficult and labor intensive it is to keep their copper bare and exposed?
 

Markoni35

TS Maniac
The entire reason for having specialized skin cells is that they die so the rest of your cells stay protected. Skin cells dying is not a problem(unless it happens at a sufficiently massive scale, obviously). It's only a problem if they DON'T die and develop into a cancer instead(which can happen in case of UV-light, for instance).
If your skin cells are dying too fast, you develop old-skin spots. Because skin cells, like most of other cells, have a limited regeneration count. Once you spend all that, you get skin like old-people have. Even if you're not old.