In 2005, realizing that many electronic devices are idle for much of the time, the team began developing new technologies to lower microprocessor energy use during sleep cycles. As Sylvester notes, “This low-power technology allowed us to scale the solution down to a much smaller size and extend product lifetime on a much smaller battery.”

One early application of their technology was an implantable device for glaucoma diagnosis and monitoring, developed for the University's W.K. Kellogg Eye Center. Their faculty collaborator on that project was Dr. Paul R. Lichter, chair of the Department of Ophthalmology and Visual Science.

"That was a tipping point for us, the point at which we asked: what are these applications really good for?" Blaauw recalls. "Working in our favor was the fact that we could make the chips useful across a broad range of applications, from electronics to smart credit cards to wireless sensors in buildings. That versatility enabled us to target a huge range of applications with essentially the same product. The key, we decided, was to tackle them sequentially."

In 2008, Blaauw, Sylvester, and Hanson engaged Tech Transfer for business development assistance, and to explore funding opportunities for further product development. The result was $150,000 from the College of Engineering Translational Research fund (ETR), and Gap funding through U-M Tech Transfer.

Ambiq Micro was officially launched in the fall of 2010. That same year, the start-up earned $330,000 in business plan competitions, some sponsored by leading venture capital firms such as Draper Fisher Jurvetson.

Now, with the help of U-M Tech Transfer Mentor-in-Residence David Hartmann, the new company has lined up prospective customers in key markets. And with approximately $2 million in venture capital commitments, Ambiq is on track to meet its goal of having sample units in the hands of potential customers in 2011.

From that spark, Hanson helped develop a technology ideally suited for very small devices with a wide range of potential applications. These include sensors for smart buildings and smart homes, sensors for industrial monitoring, body-worn medical electronics, next-generation smart credit cards, and a growing list of ubiquitous computing applications.

"Ambiq Micro is leading the way towards ubiquitous computing," said Phil O'Niel in the one-minute elevator pitch at the RBPC, "where microcontrollers are embedded in everything from the clothes that we wear to the paint on the wall. Unlike the processor wars of the last decade, it’s not going to be the company with the fastest chip, but the company with the most energy-efficient chip that's going to win the day. To capitalize on this opportunity, Ambiq Micro has developed and will sell the world’s most energy-efficient microcontroller, consuming orders of magnitude less power than what’s currently on the market today."

The company's first research prototype is currently being tested, putting this new company on track for finding their first commercial customers.

"Our system can run nearly perpetually if periodically exposed to reasonable lighting conditions, even indoors," said David Blaauw, an electrical and computer engineering professor. "Its only limiting factor is battery wear-out, but the battery would last many years."

The new sensor spends most of its time in sleep mode, waking briefly every few minutes to take measurements. Its total average power consumption is less than 1 nanowatt. A nanowatt is one-billionth of a watt.

The developers say the key innovation is their method for managing power. The processor only needs about half of a volt to operate, but its low-voltage, thin-film Cymbet battery puts out close to 4 volts. The voltage, which is essentially the pressure of the electric current, must be reduced for the system to function most efficiently.

"If we used traditional methods, the voltage conversion process would have consumed many times more power than the processor itself uses," said Dennis Sylvester, an associate professor in electrical and computer engineering.

One way the U-M engineers made the voltage conversion more efficient is by slowing the power management unit's clock when the processor's load is light.

"We skip beats if we determine the voltage is sufficiently stable," Sylvester said.

The system, in the process of being commercialized, could enable less-invasive ways to monitor pressure changes in the eyes, brain, and in tumors in patients with glaucoma, head trauma, or cancer, the scientists say. In the body, the sensor could conceivably harvest energy from movement or heat, rather than light.

This research, presented today at the International Solid-State Circuits Conference in San Francisco, was funded by the National Science Foundation, the Defense Advanced Research Projects Agency, the National Institute of Standards and Technology, the Focus Center Research Program and ARM.

The engineers say successful use of an ARM processor — the industry’s most popular 32-bit processor architecture — is an important step toward commercial adoption of this technology.

Greg Chen, a computer science and engineering doctoral student, will present the research Feb. 9 at the International Solid-State Circuits Conference in San Francisco.

“Our system can run nearly perpetually if periodically exposed to reasonable lighting conditions, even indoors,” said David Blaauw, an electrical and computer engineering professor. “Its only limiting factor is battery wear-out, but the battery would last many years.”

“The ARM Cortex-M3 processor has been widely adopted throughout the microcontroller industry for its low-power, energy efficient features such as deep sleep mode and Wake-Up Interrupt Controller, which enables the core to be placed in ultra-low leakage mode, returning to fully active mode almost instantaneously,” said Eric Schorn, vice president, marketing, processor division, ARM. “This implementation of the processor exploits all of those features to the maximum to achieve an ultra-low-power operation.”

The sensor spends most of its time in sleep mode, waking briefly every few minutes to take measurements. Its total average power consumption is less than 1 nanowatt. A nanowatt is one-billionth of a watt.

The developers say the key innovation is their method for managing power. The processor only needs about half of a volt to operate, but its low-voltage, thin-film Cymbet battery puts out close to 4 volts. The voltage, which is essentially the pressure of the electric current, must be reduced for the system to function most efficiently.

“If we used traditional methods, the voltage conversion process would have consumed many times more power than the processor itself uses,” said Dennis Sylvester, an associate professor in electrical and computer engineering.

One way the U-M engineers made the voltage conversion more efficient is by slowing the power management units clock when the processor’s load is light.

“We skip beats if we determine the voltage is sufficiently stable,” Sylvester said.

The designers are working with doctors on potential medical applications. The system could enable less-invasive ways to monitor pressure changes in the eyes, brain, and in tumors in patients with glaucoma, head trauma, or cancer. In the body, the sensor could conceivably harvest energy from movement or heat, rather than light, the engineers say. The inventors are working to commercialize the technology through a company [Ambiq Micro] led by Scott Hanson, a research fellow in the Department of Electrical Engineering and Computer Science.

The paper is entitled “Millimeter-Scale Nearly Perpetual Sensor System with Stacked Battery and Solar Cells.”

This research is funded by the National Science Foundation, the Defense Advanced Research Projects Agency, the National Institute of Standards and Technology, the Focus Center Research Program and ARM.