Microbolometer Advantages and Disadvantages

This page covers the advantages and disadvantages of Microbolometers. It mentions Microbolometer advantages or benefits and Microbolometer disadvantages or drawbacks.

What is a Microbolometer? (Introduction)

• The microbolometer is a specialized bolometer, crafted as an uncooled thermal sensor.
• It serves as a detector in thermal cameras or thermal imaging equipment.
• Figure 1 depicts a cross-sectional view of a microbolometer with different layers. It consists of an infrared absorber, a reflective layer (e.g., titanium mirror), and a readout circuit or silicon substrate.

• When infrared radiation strikes the detector material, it heats up and consequently changes its electrical resistance.
• This change in resistance is measured and used to create an image.
• Typically, some amount of light passes through the absorbing layer. This is reflected back by a reflector to ensure the greatest possible absorption can be achieved. This allows for the production of a stronger signal using the microbolometer.
• Microbolometer arrays come in various sizes, such as 320 x 240 pixels, 160 x 120 pixels, 640 x 480 pixels, or 1024 x 768 pixels.

Benefits or Advantages of Microbolometers

Following are the benefits or advantages of Microbolometers:

• It does not require cooling, unlike other IR detecting equipment. Hence, it can be operated at room temperature.
• They are smaller and lightweight.
• They consume less power compared to cooled detector thermal imaging devices.
• They have a higher MTBF (Mean Time Between Failures) value, and therefore a longer lifespan.
• Microbolometers are less expensive compared to cooled detector-based cameras.

Drawbacks or Disadvantages of Microbolometers

Following are the drawbacks or disadvantages of Microbolometers:

• The sensitivity of this type of thermal detector is lower compared to photon detectors or cooled thermal imagers.
• Response time is longer compared to photon detectors.
• They cannot be used for multi-spectral or high-speed infrared (IR) applications.
• They cannot match the resolution in comparison to cooled semiconductor-based methods.
• They have higher noise compared to cooled semiconductor methods, which may interfere with the desired signal significantly.