— In anticipation of a new federal safety requirement
for passenger cars and trucks, engineers are busy
perfecting a tiny sensor that can be placed on the
wheels to monitor tire pressure and deliver accurate
information to the driver.
The new ruling affects 17 million
vehicles each year and represents a lucrative marketing
opportunity for the manufacturers of micro-electro
mechanical systems (MEMS), which possess the technical
skills and expertise to design a miniature tire-pressure
system that is functional and, at the same time, able
to withstand extreme temperature and vibrations.
The sensor is made to attach
inside the rim of the wheel, where the MEMS device
measures tire pressure and transmits the data to a
central receiver in the vehicle. The receiver then
analyzes the data and displays it the driver in the
form of numerical readouts as well as warning lights
signaling a potential hazard.
According to Mechanical Engineering
magazine, the pressure sensor is a high-tech device
containing several components in a single electronic
package. These components include a temperature sensor,
voltage sensor, accelerometer, micro-controller, antenna,
“Each of these micro-devices
performs a task that allows a tiny integrated module
weighing 30-40 grams to measure the pressure, condition
the signal, and transmit the data,” says Mechanical
Engineering, which includes a report in the April
One engineering challenge,
according to the magazine, is powering the device.
While the typical tire-pressure device contains a
battery, some MEMS manufacturers are experimenting
with systems that obtain power from different sources,
such as an external radio frequency that transmits
energy waves to an antenna located in the wheel well
of the car or truck.
Another challenge is to protect
the delicate electronics in the tire-pressure modules
from extreme external conditions, such as vibration
and corrosion. Solutions include sealing the module
with silicone or welding a protective cover over the
Manufacturers are currently
taking their prototypes to auto and tire companies.
Market forecasts call for 76 million MEMS devices
To access the April 2005 issue
of Mechanical Engineering, including the article “Pumped
Up,” visit the ASME Web site at http://www.asme.org.
Founded in 1880 as the American
Society of Mechanical Engineers, today’s ASME is a
120,000-member professional organization focused on
technical, educational and research issues of the
worldwide engineering and technology community. In
2005, ASME celebrates 125 years of continued service
and leadership – setting the standard for professional
engineering societies worldwide