While both “Glass Micro Melt” (often called Micro-fused) and Silicon-Silicon (often called Silicon-on-Silicon) chips are MEMS-based technologies, they differ fundamentally in how the silicon sensing element is attached to the body of the sensor.

The choice between them usually comes down to a trade-off between ruggedness for harsh mechanical environments (Micro-fused) vs. high precision/miniaturisation (Silicon-Silicon).

1. Glass Micro Melt (Micro-fused) Sensors

In this technology, silicon strain gauges are bonded to a stainless steel diaphragm using a glass frit (high-temperature glass powder) that is melted at high temperatures (sintered).

• Construction: Small silicon “islands” are essentially glued to a metal diaphragm with a thin layer of glass.
• Key Advantage: It combines the high sensitivity of silicon with the mechanical strength of stainless steel. Because the glass bond is inorganic, it doesn’t “creep” or age like organic adhesives/glues.
• Durability: Excellent for high-pressure applications, heavy vibration, and hydraulic shock. Since the media (fluid) only touches the stainless steel diaphragm, it is very robust.
• Limitation: It is slightly less accurate than pure silicon-silicon chips because the glass layer and the metal diaphragm have different thermal expansion rates, which can introduce small errors.

2. Silicon-Silicon (Silicon-on-Silicon) Sensors

These sensors use fusion bonding or anodic bonding to join two silicon pieces (or silicon to a silicon-dioxide/SOI layer) directly at the atomic level.

• Construction: The entire sensing structure—the diaphragm and the frame—is made of silicon. There is often no intermediate material like glass or metal in the active sensing area.
• Key Advantage: Absolute Stability. Because the entire structure is the same material, there is no “thermal mismatch.” If the temperature changes, the whole chip expands and contracts at the exact same rate.
• Precision: These offer the highest possible accuracy and long-term stability. They are the gold standard for low-pressure measurements (like medical ventilators or cleanroom monitoring).
• Limitation: They are more fragile. Because the diaphragm is made of brittle silicon, they can be easily destroyed by pressure spikes or “water hammer” effects in hydraulic systems.

Comparison Summary

Would you like me to help you determine which type is better suited for a specific fluid or pressure range you are working with?