In this work, films of horizontally aligned single-walled carbon nanotubes were thermally and electrically characterized in order to determine the bolometric performance. An average thermal time constant of τ = 420 μs along with a temperature coefficient of resistance of TCR = -2.94% K(-1) were obtained. The maximum voltage responsivity and detectivity obtained were R(V) =230 V/W and D* = 1.22 × 10(8) cm Hz(1/2)/W, respectively. These values are higher than the maximum voltage responsivity (150 V/W) and maximum temperature coefficient of resistance (1.0% K(-1)) previously reported for carbon nanotube films at room temperature. The maximum detectivity was obtained at a frequency of operation of 1.25 kHz.

Single-walled carbon nanotubes (SWNTs) have shown interesting bolometric properties, making them good candidates for the detection of infrared and terahertz radiation. However, little has been reported on the bolometric characteristics of SWNT as a function of their chirality or the possible influence of composite morphology on these properties. The separation of SWNTs based on chirality allows for almost purely semiconductive or metallic SWNTs to be studied. The current study focuses on the bolometric performance of self-assembled composite films of SWNTs. The dependence of these properties on the chirality of the SWNTs was evaluated. To this end, metallic, semiconducting, and a 1:1 mixture of metallic and semiconductive were studied. Also, a theoretical model based on the Wiedemann−Franz law is used to explain the resistance of the SWNT composite films as a function of temperature. Results show that the composite morphology has a significant impact on bolometer performance, with cracked composite films containing highly aligned SWNT arrays suspended over a silicon substrate showing superior responsivity values due to higher thermal isolation. Uncracked composite films showed superior thermal coefficient of resistance values (α = −6.5%/K), however, the responsivity was lower due to lower thermal isolation.

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Multi-Walled Carbon Nanotubes (MWNTs) are a good choice for resistive biosensors due to their great resistance changes when immunoreactions take place, they are also low-cost, more biocompatible than single-walled carbon nanotubes, and resistive measurement equipment is usually not expensive and readily available. In this work a novel resistive biosensor based on the immobilization of an antigen through a silanization process over the surface of Multi-Walled Carbon Nanotubes (MWNTs) is reported. Results show that the biosensor increases its conductivity when adding the antigen and decreases when adding the antibody making them good candidates for disease diagnosis.