A large-area single-filament infrared emitter and its application in a spectroscopic ethanol gas sensing system

• Published in: Microsystems & nanoengineering Vol. 7; no. 1; p. 87
• Main Authors: Schröder, Stephan, Briano, Floria Ottonello, Rödjegård, Henrik, Bryzgalov, Maksym, Orelund, Jonas, Gylfason, Kristinn B., Stemme, Göran, Niklaus, Frank
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.10.2021; Springer Nature B.V; Nature Publishing Group
• Subjects: 639/166/987; 639/624/1075/1083; Aluminum alloys; Broadband; Carbon dioxide; Chemical sensors; Consumer applications; Costs; Emission spectroscopy; Emitters; Engineering; Ethanol; Frequency dependence; Frequency response; Gas detectors; Gas sensors; Gas-sensing systems; Gases; Highly accurate; Infrared emitters; Infrared heating; Infrared spectroscopy; Iron alloys; ITS applications; Low cost; Low-costs; Maintenance free; Non-dispersive infrared; Ohmic dissipation; Power consumption; Resistance heating; Single filaments; Spectrum analysis; Substrates
• ISSN: 2055-7434; 2096-1030; 2055-7434
• DOI: 10.1038/s41378-021-00285-8

Nondispersive infrared (NDIR) spectroscopy is an important technology for highly accurate and maintenance-free sensing of gases, such as ethanol and carbon dioxide. However, NDIR spectroscopy systems are currently too expensive, e.g., for consumer and automotive applications, as the infrared (IR) emitter is a critical but costly component of these systems. Here, we report on a low-cost large-area IR emitter featuring a broadband emission spectrum suitable for small NDIR gas spectroscopy systems. The infrared emitter utilizes Joule heating of a Kanthal (FeCrAl) filament that is integrated in the base substrate using an automated high-speed wire bonding process, enabling simple and rapid formation of a long meander-shaped filament. We describe the critical infrared emitter characteristics, including the effective infrared emission spectrum, thermal frequency response, and power consumption. Finally, we integrate the emitter into a handheld breath alcohol analyzer and show its operation in both laboratory and real-world settings, thereby demonstrating the potential of the emitter for future low-cost optical gas sensor applications.