TM

American Sensor Technologies • 450 Clark Dr., Mt. Olive, NJ 07828 • phone (973) 448-1901 • fax (973) 448-1905 • email: info@astsensors.com

© 2010 American Sensor Technologies Inc.www.astsensors.com

Krystal™ Bond Technology

Oil Filled

Ceramic

Thin Film / Bonded Foil

Yield Point

STRAINε

STRESSσ

ELASTICREGION

PERMANENTDEFORMATION

X “Fracture”(for metal)

0 275 με 1000 με 2000 με

MEMS Pressure Sensor Technology“Krystal Bond™ Technology is the latest MEMS (Micro Electro-Mechanical System) pressure sensor technology. Using a single piece of metal and MEMS strain gages, this technology provides accurate, repeatable measurements.” - Karmjit Sidhu, Vice President Business Development, AST Co-Founder, and Material Science PhD candidate at the New Jersey Institute of Technology (NJIT).Close up photo of Krystal Bond Technology, showing silicon strain gages on a metal diaphragm

The strain gages are molecularly diffused onto the metal diaphragm surface using inorganic materials and high temperatures. As the temperature is reduced, the inorganic bonding material solidifies and secures the silicon strain gauge into position above the center of the sensor, thus creating the one piece sensing element.

Why use Krystal Bond™ Technology?With an operating strain at less than fifteen percent (15%) of the metal’s yield point, the AST pressure sensor cell has less fatigue, higher proof/burst pressure capability, and excellent long term stability. A simple example of this is inflating and deflating a balloon several times. The stretching and distortion depends on the thickness of the balloon. The principles of pressure measurement are the same. As

a diaphragm is pressurized closer to the yield point, a transformation in the shape occurs, changing the output over time. Krystal Bond™ Technology would be similar to inflating the tires on a bicycle or car with the same method.

Stress to strain curve of pressure sensor technologies outlining the relationship between the technology, yield point and fracture point of the materialBy using inorganic materials in the process bonding the strain gages to the diaphragm, there is virtually an infinite shelf life to the pressure sensing element. AST’s strain gages also yield a high output signal with low thermal errors.

The typical pressure sensor includes a pressure port thread, hex and diaphragm. All three components for AST are a single element. A bar of metal has the outside shape

machined and the inside hole bore. The media is completely contained within the sensing element. Other sensor technologies can clamp a ceramic diaphragm with an O-ring, use an oil-filled cavity to transfer pressure, or weld a diaphragm onto the pressure port. Krystal Bond™ simplifies your system with one material and no leak paths. By designing the pressure sensor cell with one piece of material, AST has eliminated weak points and contamination risks.

The AST sensing element provides a high electrical isolation with low leakage rates at 500VAC, making Krystal Bond™ Technology ideal for process control applications, including CSA certification.

Krystal Bond™ Technology can be used on a variety of materials including 17-4PH, 316L, Inconel718, and Titanium, which are designed in different package sizes to meet customer demands. From sour gas in the oil patch to medical pumps in the human body, ourMEMS technology can be matched to a variety of media requirements. Technology

by AST

TMBondKrystal