Figure 3
From: A highly stable, nanotube-enhanced, CMOS-MEMS thermal emitter for mid-IR gas sensing
Nondispersive infrared (NDIR) experiment. (a) Schematic of the NDIR gas sensor setup. (b) Relative optical response, recorded by the thermopile at 4.26 \(\upmu\)m, for an uncoated (black line), CNT-coated (dotted blue line), and encapsulated (red line) micro-hotplate respectively. The detected IR emission from the unencapsulated device (dotted blue line) drops rapidly (minutes) at temperatures above 600 \(^{\circ }\)C, consistent with data presented in Fig. 2b. (c) CO\(_2\) sensor response voltage with an uncoated (black line), and encapsulated (red line) micro-hotplate respectively. A \(\sim\) 8-fold increase in relative voltage \(\Delta V=V_{0 ppm}-V_{lock-in}\) can be observed for the encapsulated CNT device.
