Science Interviews

Giving Insects the Slip

Kat -   Also this week, researchers at Cambridge University have developed a new insect repellent coating which could help to reduce a threat of cockroaches.  Now for many of us, insects are just kind of a bit of a pest.  They get in your picnic.  But insect infestations are responsible for billions of pounds worth of damage across the globe every year.  Now we’re joined by Jan-Henning Dirks from Cambridge University.  So, tell me a bit about what the problem is with insects and then how you've tried to counteract this.

Jan -   Yeah, well the problem with insects is that they amazingly well stick to all kinds of surfaces.  As you look around you, you see them basically clinging to the mirror, clinging to the window, holding on to everything and holding on very, very tight.  And so, for us, this is a more scientific problem to understand how this actually works.  So at the Insect Biomechanics Workgroup here in Cambridge, we were trying to figure out what makes insects so incredibly good at sticking to different kinds of surfaces and whilst we were exploring this, we found a surface that can help you prevent your house and your belongings, and probably even your lab from crawling insects.

Kat -   So how does this surface work?  Because we have nonslip surfaces, things like PTFE that we cover non-stick pans with.  Why is your surface different?  How does it work?

Jan -   Well, our surface is completely different to all other insect repellents that you know.  Because if you look around you, all insects that you can see, they have sweaty feet actually, so they have it...

Kat -   Nice...

Jan -   They do, yes.  And you can even write your PhD about it!  And so, the foot sweat that they have that helps them to stick to surfaces and our technology does something very new.  It basically – it tricks the insect’s feet.  It makes them lubricate their own feet.  Other repellents that you see, they work, like, they are sticky themselves so you know, these fly tapes that capture flies or some people who insects at home, they know that.  They have this surfaces that erode and make the feet dirty.  But our technology is like a selective sponge that removes something from the insect’s adhesive fluid and what’s leftover, makes the insect’s feet slip.

Kat -   So, instead of having sort of a sticky glue that they're sticking on the wall with, suddenly they're going, “Wooh!” and sliding off.

Jan -   It’s very similar.  So they don’t really have the sticky substance at first.  It’s more like ketchup or custard.  It’s one part of it is oil and the other part is water.  And together, it works very similar to ketchup.  But if we remove the water, that’s what our surface does, then what’s leftover is the oil on that then make insects slip.

Kat -   And tell me a bit more about the surface.  I mean, what sort of things can we coat with it?  Is it very pliable?

Jan -   So, that’s what we’re exploring right now.  So in theory, you can apply the surface to a very, very many kinds of different substances.  Right now, we’re exploring and that’s why we’re looking for commercial partner to make this really available for everyone so they can coat whatever they want with it and make insects slip from the barbecue or from where they don’t want insects to be.

Kat -   Fantastic.  Well, I'm looking forward to an non-insect to non-stick picnic camp and that would be fantastic.  That was Jan-Henning Dirks from Cambridge University.

October 2009