Spatial Thermal Gradient Mapping Micro-Machined Accelerometer Arrays
Spatial thermal gradient mapping in micro-machined accelerometer arrays decouples linear motion from external board heat using differential thermopile matrices.
Heater Micro-Bridge
Thermal Element
Micro-electromechanical structures suspended over a silicon substrate provide localized thermal excitation for gas flow or chemical sensing. By using a heater micro-bridge, the system can reach high temperatures with minimal power consumption due to the low thermal mass of the suspended beam. The gap between the bridge and the wafer provides thermal isolation.
This structure allows for rapid heating and cooling cycles.
Power Efficiency
Direct resistive heating occurs within the thin film layer of the bridge. Because the heater micro-bridge is physically small, it requires only milliwatts of power to reach operating temperatures of several hundred degrees. This efficiency makes the component suitable for portable, battery operated instruments.
Structural Stability
Mechanical stress from repeated thermal cycling can lead to the deformation or breakage of the suspended layer. A well designed heater micro-bridge uses materials with matched coefficients of thermal expansion to prevent buckling. Manufacturers verify the integrity of these bridges through accelerated life testing.
Response Timing
Short thermal time constants are the primary advantage of this architecture. A heater micro-bridge can respond to pulses in the kilohertz range, enabling high speed sampling of gas mixtures. This speed is restricted by the heat capacity of the bridge material and the thermal conductivity of the surrounding gas.