EE Est. 1889
CE Est. 1971

Research

A Fantastic Voyage: ERC for WIMS

The first-ever Engineering Research Center in Wireless Integrated Microsensing and Systems forged advances in many fields

In 2000, Michigan became home to the first National Science Foundation-funded Engineering Research Center (ERC) for Wireless Integrated MicroSystems (WIMS).

This was no overnight occurrence. Rather, it was the result of a quarter-century of Michigan Engineering-based advances in neural probes, low-power electronics, wireless communications, microelectromechanical systems (MEMS), innovative power sources, and advanced packaging.

Cochlear Implants

 

cochlear implant Achieved in 2005, this is the first use of thin-film technology for cochlear electrode arrays, with increased pitch resolution and better insertion tools. This thin-film silicon-parylene cochlear array incorporated 32 IrO stimulating sites along with 8 position-sensing strain gauges, and communicated over an 8-lead cable with an implanted microprocessor and bidirectional wireless link.

Over the next ten-year period – under the direction of Kensall Wise, William Gould Dow Distinguished University Professor Emeritus, and deputy director Khalil Najafi, Schlumberger Professor of Engineering – the Center developed cutting-edge technology for hearing, brain research, and biomedical/environmental sensing. It also authored 59 patents, and 11 spinoff companies that would further work incubated at the Center.

In 2010, the Center was renamed the Center for Wireless Integrated MicroSensing and Systems (WIMS2), and Yogesh Gianchandani became its director. Wireless integrated microsystems were by then becoming pervasive in applications such as health care, environmental monitoring, infrastructure monitoring, homeland security, and defense, and enhanced technology was enabling a ready linkage between the electronic and the physical worlds through pervasive sensing devices, which were helping to create the “Internet of Things.”

The Voyage Begins - and Accelerates

Professor Wise influenced virtually every advance in wireless integrated microsystems research during the latter part of the 20th century.

Just two years after he arrived in 1974, Michigan produced the world’s first pressure sensor with on-chip readout circuitry. The first silicon micromachined infrared detectors were introduced in 1980, followed by neural probes for exploring the central nervous system. Groundbreaking research in microelectromechanical systems (MEMS), which integrate sensors, actuators, and electronics on a common platform, was conducted in the 1980’s. This research led to the world’s first functional integrated gyroscope in 1993 and the first reported integrated ring gyro in 1994. By the mid 1990’s, Michigan neural probes were being distributed worldwide and development of microsystems for environmental monitoring was underway.

By 2000, feature sizes had dropped below 100nm, and new applications were sought that required very-low-power microsystems with integrated circuits, sensors, and wireless interfaces.

In shotr order, the Center had shown the feasibility of moving beyond components to the system level, creating full microsystems capable of solving important societal problems. 

Problem-solving Applications

Among the Center’s major contributions and advancements:

  • The demonstration of a cell-phone-size gas chromatograph (µGC), and a prototype for a palm-size (100cc) microsystem.  These systems have important applications in healthcare, defense, manufacturing, planetary exploration, and the mapping of global pollution.
  • An intraocular pressure sensor for the treatment of glaucoma that used the Phoenix processor, a solar energy scavenging, and a novel glass-in-silicon process
  • A cochlear microsystem to restore hearing to the profoundly deaf that used a specially-developed microcontroller along with an inductively-coupled wireless interface for power and data transfer
  • New neural interfaces that helped to spark the revolution in neuroscience and neural prostheses, including smart stents for improved cardiovascular care: biopsy needles capable of measuring local tissue density as an aid in diagnosing cancer; hand-held breath analyzers for detecting the biomarkers of tuberculosis and lung cancer; wristwatch-sized radiation detectors for ensuring the safety of containerized shipping; and air-quality monitors for protecting the global environment. Many of these microsystems were the first of their kind.

The WIMS ERC Legacy

In addition to advancing technology, the Center played a pivotal role in other realms as well. Its active outreach program successfully included underrepresented minorities, females, and teachers: 61% of its short course enrollees were underrepresented minorities, and approximately 38% of its 3,424 K-12 Center participants were minorities. And more than 60% of its participating high school graduates would later enter a college engineering program.

During its decade-long reign, nearly 60 faculty members – representing 16 different interdisciplinary departments from 10 universities had – made significant contributions to the Center’s work. More than 1,200 journal articles and conference papers were published and presented at major MEMS/microelectronics conferences. WIMS research was featured on the cover of Neuron, SensorsAnnals of Vascular SurgeryEE TimesJournal of Neurophysiology, and Hearing Research. And the Center graduated 160 doctoral, developed five new courses, and created a program in Integrated Microsystems.

The Center also forged strong international partnerships. Its industrial partnership program alone included more than 40 companies. A study funded by the NSF estimated that during the 1990s the Center generated a $400 million economic benefit to the State of Michigan.

Palm-sized Gas Chromatograph

HERCULES Laser University of Michigan The WIMS gas chromatograph, achieved in 2010, was the first palm-size integrated uGC system every implemented, and included temperature control electronics, an embedded processor, and a USB interface. It was 100x smaller, 100x cheaper, and 100x faster than anything on the market. Such devices were expected to revolutionize security, environmental monitoring, food processing, and health care by enabling low-cost, widely-deployable gas analysis. These devices may one day determine tuberculosis and lung cancer just through breath analysis.

 

Biomedical and Environmental Sensing

HERCULES Laser University of Michigan Implanted in the iris of eye, these tiny sensors in hermetically-sealed glass packages measured intraocular pressure every 15 minutes, wirelessly transmitting the data to the healthcare provider daily.

HERCULES Laser University of Michigan Featured on the cover of Annals of Vascular Surgery, this 2004 wireless sensor measured pressure and flow in the carotid arteries. This was the first active stent incorporating active electronics ever reported.

2005 microsystem This 2005 microsystem pioneered multi-chip integration and was capable of sensing pressure, temperature, humidity, and biomedical signals.

 

Low-power Microprocessors

HERCULES Laser University of Michigan The WIMS “Phoenix” processor, developed for the intraocular implant, dissipated only 30pW in standby mode, and 2.8pJ/instruction at 0.5V. In 2008, the Phoenix microprocessor became the world’s lowest-power processor with its 20pW, 1mm2 platform for sensing applications.

 

Neural Probes
2002 neural probe This 96-site neural probe containing on-chip CMOS circuitry, developed in 2002, was the first to record chronic single-unit activity in freely ranging animals, to better understand learning and memory formation.