Ali Dhinojwala has a story he likes to tell.
The University of Akron polymer-science professor’s tale begins in 17th century India, where legend says a Hindu prince named Shivaji came upon a unique way to attack his enemy’s hilltop fortress.
Shivaji attached gecko lizards to his warriors’ hands and used the geckos’ remarkable adhesive abilities to climb the sheer cliffs and surprise the stronghold.
But this is more than a myth for Dhinojwala. He has been studying gecko feet — almost 30 geckos are kept in the University of Akron biology department — for the last 10 years. And in 2010, Dhinojwala started ADAP Nanotech, a company that aims to synthetically recreate the lizard’s adhesive ability for products that keep electronics cool and stop ice from forming on aircraft wings.
Geckos have long fascinated scientists because of their ability to scale walls, walk on ceilings and stick to even the most difficult surfaces while still moving easily.
“We started off as a very fundamental project,” says Sunny Sethi, a co-founder of ADAP Nanotech and the company’s materials scientist. “Our goal from the university’s perspective was to understand the physics by which adhesion occurs.”
Researchers from all over the world have tried to unlock the secrets to the lizard’s abilities. Eventually they discovered that a gecko’s foot is covered with microscopic hairs that branch into smaller hairs at the ends. This brushlike structure creates a strong friction adhesion in one direction that allows the lizard to bond very easily yet quickly lift its toes to move in the other direction.
“The trick geckos have is the millions of small hairs,” Sethi says. “When a gecko puts its foot on any surface, these hairs bend and buckle and allow for very good contact.”
There’s a stickiness at a molecular level. Because the atoms are so close together, they have an attractive interactivity, he says. Once the University of Akron scientists understood the biomechanics of the gecko’s feet, they attempted to replicate those tiny hairs.
In 2005, Dhinojwala figured something called a carbon nanotube might be the answer. This is an infinitesimally small piece of graphite that forms a tubelike structure. Ten thousand would have to be piled together to be seen with the naked eye.
Dhinojwala believed their potential was huge. By 2007, Sethi had joined in the search to commercialize their research, initially focusing on making it into a kind of adhesive tape. Though the commercial applications seemed vast, the duo also saw potential in the electronics industry.
An array of carbon nanotubes are very conductive — 10 times more conductive than copper and three times more conductive than the polymers currently used in electronics — which could make them a staple of consumer electronics. As processors get smaller and more powerful, they generate more heat. As a result, electronics manufacturers need better conductors to get that heat away from the processor.
ADAP has created a thermal pad, called NanoTIM, composed of millions of these carbon nanotubes placed on very thin silica and polymer layers. The resulting material is strong and conductive like a metal but able to fill tiny gaps almost like a liquid.
“The current technologies are bumping against their limits,” says Rem Harris, vice president for investments at JumpStart, which assists Northeast Ohio startups. “The objective [for ADAP Nanotech] is to create a more conductive material that pulls heat from the processor.”
Before the company can line up customers, however, it needs to produce samples that can be evaluated by potential buyers. That means Sethi’s main concern right now is ramping up production.
JumpStart gave ADAP Nanotech a $250,000 grant in February to build a pilot production facility on the eighth floor of the Akron Global Business Accelerator. It is expected to be operational by July. Once up and running, the company will send samples to prospective customers and start hiring its first employees.
“We’re trying to solve the manufacturability issue to produce these materials at the right price and in the right quantity,”
To grow carbon nanotubes, Sethi pumps a series of gasses into a furnace he designed and built. When the furnace reaches 1,500 degrees, the gasses interact and break down. What’s left are carbon nanotubes. Grown in large arrays, the carbon nanotubes (which individually are 1/10,000 the size of a human hair) look like a black, sooty material, Sethi says.
“You have to use an electron microscope to see the structures that we make,” Sethi says. “They are really, really small.”
It’s the smallness that makes them so effective. The nanotubes, like the hairs on a gecko’s foot, are numerous and also bend on contact with another surface, creating nearly perfect coverage.
“It’s really a quite simple mechanism,” Sethi says.
From an investment standpoint, JumpStart was impressed that ADAP’s technology had more than one application. Yet, it was important that the young company focus on one application from the start and not try and spread itself too thin.
“They need to target markets they can penetrate quickly,” Harris says. “We felt their technology would have a strong value proposition within thermal interface materials.”
ADAP Nanotech’s advisers, James A. Latham and Robert Sturgill, have extensive experience. Latham was a co-founder of Thermagon, which made thermal gap fillers and was eventually purchased by Laird Technologies. Sturgill, meanwhile, was founder and CEO of Enigma Semiconductor Inc.
“They’re providing advice, but also opening doors to potential customers who can look at samples and critique it,” Harris says. “They need to develop relationships with organizations that will evaluate the product.”
For Sethi, one of the most exciting things is that the business could go in a number of directions. Not surprisingly, he and Dhinojwala have started talking with adhesive companies. Their carbon nanotubes, which repel moisture and dirt, may also help make air travel safer. “Ice will not form on these surfaces, so there are applications for airplane wings,” Sethi says.
But that is all down the road, a long road with many potential destinations.
“It’s possible that after two years, we’ll have a different business plan,” he says. “Maybe another industry will take interest.”