Tick-killing robot is brainchild of engineering professor

Jim Squire's daughter got a tick one day, and so did his dog.

The engineering professor didn't like it.

Shortly afterward, a colleague at Virginia Military Institute brought him a souvenir from a robotics competition: a little tank-treaded robot chassis.

"He was turning it over in his hands, and I could see he was also turning it over in his head," said the colleague, David Livingston, also an engineering professor.

Soon, along with a third professor, they had invented a tick-killing robot.

Simple as that.

The engineers knew a lot about robots when they started, but not much about ticks. They turned to Old Dominion University, where Livingston had studied, home base of world-renowned tick expert Daniel Sonenshine.

Sonenshine suggested making the ticks chase the robot instead of the other way round.

So that's what they did.

Ticks are attracted to the carbon dioxide given off in an animal's breath, and they're attracted to movement.

The engineers laid tubing that emits a small amount of carbon dioxide alongside a magnetic wire that the robot follows. About 15 minutes after the tube starts "breathing," the robot trundles slowly down the line, dragging a piece of denim fabric behind it. The denim is treated with a pesticide.

Ticks that have been lured to the carbon dioxide grab the denim, and the pesticide kills them.

Simple.

Holly Gaff, an associate professor at ODU who specializes in mathematical modeling and simulation of infectious diseases, especially those carried by ticks, was called in to test the robot.

Much of her research over the past five years has been conducted at Hoffler Creek Wildlife Preserve in Portsmouth.

"We have lots and lots and lots of ticks here," she said. "Our basic procedure was to go out the day before, collect every tick we could find, paint them with fingernail polish, and put them back."

Yes, 12 different colors of fingernail polish, applied with toothpicks.

"It is a skill set I never thought I would have to acquire," Gaff said.

The polish enabled researchers to identify when each tick was caught and the re-capture rate, among other experimental factors. They did a lot of painting.

Hampton Roads has many varieties of ticks, including dog ticks (the big ones), deer ticks (the little slow ones, also called black-legged ticks), lone star ticks (the little, fast ones) and Gulf Coast ticks (the golden ones).

Deer ticks can carry Lyme disease, Gulf ticks can carry Tidewater spotted fever, and a surprisingly large number of lone star ticks carry the bacteria that cause ehrlichiosis, a disease with flu-like symptoms similar to Lyme disease, according to research conducted at the College of William & Mary.

It's not your imagination — there really are more ticks than there used to be.

Humans have created a perfect tick habitat, Gaff said, by fragmenting forests and inserting houses. Squirrels, raccoons and other small animals love the habitat where woods meet grass, and ticks love animals. The rise in tick numbers also parallels the rise in the white-tailed deer population, she said, which is itself quite large.

The robot was tested first in an ODU lab, seeded with 50 ticks. The robot captured 45 on its first swipe.

"We were shocked," Livingston said. "We didn't expect it to be that efficient."

So they took it outdoors, to Hoffler Creek.

"Honestly, I told everybody I did not believe it would work to any extent," Gaff said. "I was very, very surprised to find that it actually did."

The robot killed almost 100 percent of ticks in the study zone, she said, and the area stayed clear of ticks for about 18 hours.

"You could sit and have lunch in the middle of Hoffler Creek, on the ground, and not have a tick crawl on you," Gaff said. "Having spent five years running from that place, it was neat that we could make a difference for them."

Next summer, team members plan to test the robot in residential areas. They want to know how long a yard can remain tick-free and how often treatments must be repeated.

"We're not eradicating ticks by any means; we're just very surgically eliminating them from a particular area," Livingston said. "Once we clean the yard, how long before they come back? If we can keep it clean for a number of days, then it's going to be a viable product. If they come back overnight, not so much."

The pesticide used on the denim must be handled by licensed professionals, so the team envisions the robots being used by pest-control companies. Members are pleased that the pesticide is confined to the cloth rather than spread in the environment at large, and that the amount of carbon dioxide released is similar to what a human breathes out naturally.

In your head, imagine a backyard cookout, a graduation party on the lawn, a hike on a wooded trail. Now imagine them free of ticks.

That sounds simply wonderful.