Piezo-Metrics Semiconductor Strain Gage Technology
Piezo-Metrics’ strain gages fall in the ‘Discrete silicon gage’ category. (see tables) The semiconductor strain gages are micromachined from a wafer cut from a solid single crystal of “P” doped silicon. This manufacturing process minimizes the number of molecular dislocations and results in a strain-sensitive resistive device that is capable of accurately measuring high levels of strain. Besides the characteristics listed in the ‘Discrete silicon gage’ category in Table 1, Piezo-Metrics semiconductor strain gages also have the following attributes:
- Size Our strain gages are extremely small and range in length from 0.018 in. to 0.090 in 0.46 mm to 2.3 mm. This small size makes them suitable for many applications such as implanted medical devices which have extremely limited space to mount strain gages.
- Sensitivity Piezo-Metrics’ strain gages have high gage factors ranging from 120 to 160. A high gage factor allows the sensing structure to be stiffer resulting in a more accurate measurement and a longer-term stability without sacrificing electrical output.
- Resistance We are driving the high end of strain gage impedance, currently as high as 50,000 Ω, for wireless sensing applications. High impedance gages reduce power requirements and enables the design of high output RF circuitry for greater transmission range.
Table 1 – Strain Gage Technology Comparison
| Strain Gage Technology | Advantages | Disadvantage |
|---|---|---|
| Metal foil gage |
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| Thin film gage |
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| Discrete silicon gage (Piezo-Metrics strain gages) |
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| MEMS silicon gage |
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| Discrete quartz sensor |
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