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

Abstract

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.

Graphene Thermal Infrared Emitters Integrated into Silicon Photonic Waveguides

“…Table compares the performance of our graphene emitters with the current state of the art achieved with both conventional materials and other nanoemitters. We included representative publications of thick and thin metallic thermal emitters emitting into free space. − We also covered publications on thermal graphene emitters emitting into free space − ,− and representative publications for monolayer and multilayer graphene. We extended the list to incandescent emitting materials, − which includes electroluminescent and incandescent CNT emitters coupled with photonic waveguides.…”

Application of Two-Dimensional Materials towards CMOS-Integrated Gas Sensors

“…This means that novel and complex materials need to be involved and engineered for improved performance. One such option was recently developed for ethanol (9.5 m) and CO 2 (4.3 m) detection using a single wire Kanthal (FeCrAl) alloy filament [ 84 , 85 ].…”

“…These emitters use silicon or SOI wafers to define membrane-based suspended microheater structures, not unlike those required for the SMO sensor described in Section 2.2 . MEMS IR emitters are manufactured using CMOS-compatible, high-volume semiconductor technologies, which are cost-effective for mass production [ 85 , 86 ]. The microheater material is most commonly platinum, which is not usually found in CMOS technology, but recent studies have shown the potential of using tungsten instead, which ensures smoother CMOS integration [ 81 ].…”

Development of LTCC IR-Emitter and Its Packaging

“…The thick-film can be fabricated in various substrates such as alumina, metal sheets, LTCC and HTCC. [13][14][15][16][17][18][19][20][21][22][23] LTCC based IR source has numerous advantages including its long term stability at higher temperatures, high temperature stable interconnections and cost effectiveness, low thermal conductivity, machinability to create different structures, buried and multilayer patterns, avoids issues such as high internal stress, high thermo-mechanical strength, fast turnaround time and rapid prototyping, relatively low cost. 24,25 In specific the detection of CO/CO 2 is very important and various detection principles are used for detection of these gases.…”