Microneedles inspired by mosquitos – In the news
Sophie H., East Loddon P-12 College
No one likes needles. They’re big, sharp and scary, however, we all have to have them at one point or another. But what if needles didn’t have to be this way? Researchers from Ohio state university and Osaka's Kansai University are using a mosquito (Culicidae) as their inspiration for a new design of needle. This new type of hypodermic needle would make injections a less agonising experience. The biggest difference between a regular needle and a mosquito inspired one is the fact that the edge is not smooth. It’s jagged. Immunisations currently prevent between 2 and 3 million deaths every year, however, a change to the design of needle used could prevent even more deaths.
While they are such a nuisance, the fact that mosquitos are able to puncture the skin without causing pain is amazing. They are able to do this due to their use of saliva to numb the feelings, as well the vibration of the fascicle, which is the part of the mosquito that draws the blood. The jagged edges on the proboscis or the mouth like part help to reduce the pain. But the most interesting part of the mosquito’s action of drawing blood is the fact that the proboscis of the mosquito actually varies in stiffness. It gets softer near the tip reducing the force required to pierce the skin, causing less deformation and therefore less pain (https://newatlas.com/mosquito-micro-needle/55207/ , 2018).
As well as biology knowledge, engineering will be required to design the structure of the needle, in order to make it as effective as possible. Bharat Bhushan is a professor of medical engineering at Ohio State who is working on the design of the needle. “In this work what interested us was the way that mosquitos bite, since they are able to do this for several minutes without us feeling a thing. We wanted to see if we could use this to create a painless microneedle” (https://www.digitaltrends.com/cool-tech/mosquito-microneedle-ohio-state/, 2018).
Bhushan’s design, that is soon to be tested, consists of two needles. One which numbs the area, mimicking the saliva of the mosquito and the second one is used to inject the necessary drug or draw blood. The first needle would be jagged and would be more flexible and softer towards the tip of the needle (Refer to figure below). While it would be expensive to use this needle in all cases, it would be a great beginning for children or those who have a fear of needles.
There are still several hurdles to overcome, including the fact that a mosquito’s full sting motion cannot be replicated. The needle is brittle and could break off and possibly cause a blood clot. Engineer Seiji Aoyagi claimed that we will eventually conduct human trials (https://www.newscientist.com/article/dn2121-painless-needle-copies-mosquitos-stinger/ , 2002). If these trails are successful, these microneedles become the future of our medical field.
This example of Biomimicry is fascinating because it could change the way we are giving our immunisations and reduce the pain for injecting and drawing blood samples which could increase vaccination rates and therefore reduce the risk of us developing life threatening diseases. The next step is to turn this design into a reality.
Holloway, James; June 27, 2018; Mosquitos inspire pain-free microneedle; https://newatlas.com/mosquito-micro-needle/55207/; May 13, 2019
Dormehl, Luke; June 26, 2018; Future pain-free microneedles inspired by mosquitos; https://www.digitaltrends.com/cool-tech/mosquito-microneedle-ohio-state/; May 13, 2019
Cohen, David; April 4, 2002; Painless needle copies mosquito stinger; https://www.newscientist.com/article/dn2121-painless-needle-copies-mosquitos-stinger/;May 13, 2019
The article above is one of the winning entries of GTAC's Biomimicry Blog competition. The competition challenged Victorian students to submit a blog article detailing an example of scientific and mathematical advances that were inspired by nature. Click here for more information.