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.
Differential Thermopile Matrix
Transduction Array
Arrays consisting of series-connected thermocouples generate an electrical voltage proportional to the temperature difference between two distinct sets of junctions. Within a differential thermopile matrix, the hot and cold junctions are interleaved to capture spatial gradients with high precision. This arrangement provides a passive means of signal amplification without requiring external power.
The resulting voltage is a linear function of the temperature delta.
Spatial Resolution
Positioning of the individual junctions determines the ability of the system to map thermal distributions over a small surface area. A dense differential thermopile matrix allows for the detection of micron scale heat sources in microfluidic channels. Localized variations are captured more effectively by a matrix than by a single point sensor.
Sensitivity Enhancement
Connecting the elements in a series configuration increases the total Seebeck voltage produced by the device. Every pair added to the differential thermopile matrix raises the signal to noise ratio by a predictable margin. High sensitivity is achieved by balancing the number of junctions against the total electrical resistance of the circuit.
Operational Boundary
Environmental limits for these arrays are dictated by the melting points of the thin film metals and the thermal conductivity of the substrate. Although the differential thermopile matrix is passive, its performance degrades if the substrate reaches thermal saturation. Proper heat sinking is required to maintain the reference junction temperature.