Micromachined chemical sensor with dual-transduction mechanisms

Abstract

Chemical sensors based on a microhotplate platform generally function via a conductometric or calorimetric transduction mechanism. In addition to these mechanisms, a mechanical transduction mechanism is proposed based on the detection of the microhotplate bending due to volume change of functional layers. In this letter, we demonstrate sensing of gaseous hydrogen based on volumetric expansion of Pd∕Y functional layers. In this case, the embedded polysilicon heater element also serves as the piezoresistive strain-detecting element, changing its resistance as the microhotplate bends. This transduction mechanism can be used independently of, or in conjunction with, a simultaneous conductometric or calorimetric mechanism.

Multivariable Sensors for Ubiquitous Monitoring of Gases in the Era of Internet of Things and Industrial Internet

“…433 Electrical and mechanical outputs were combined in a sensor that measured conductance and bending of the microhot plate due to volume change of functional layers. 434 Two types of electrical outputs were combined in a sensor that measured conductance and surface work function of a nanostructured graphite film. 435 These measurements were applied to discriminate several individual model gases as illustrated in Figure 44.…”

“…Thermal and mechanical outputs were combined in another sensor that measured heat dissipation and resonant damping in a microcantilevers . Electrical and mechanical outputs were combined in a sensor that measured conductance and bending of the microhot plate due to volume change of functional layers …”

“…While these discussed sensors exhibited typically 2-D response dispersion, − their design principles may be further expanded toward higher response dispersion in future sensor designs …”

A Perspective on Recent Advances in Piezoelectric Chemical Sensors for Environmental Monitoring and Foodstuffs Analysis

“…One of the promising directions in the development of novel piezosensors is the establishment of appropriate transducers, which may implement simultaneously several operations principles, thus resulting in the construction of an analytical multisystem [4,[98][99][100]. Although publications on this topic are still rare, they are of great interest in solving issues of increasing the information content and overall dimensions of sensory systems.…”

A chemiresistive-potentiometric multivariate sensor for discriminative gas detection

“…Chemiresistive (C) and potentiometric (P) are two most widely studied gas sensor transducers, both meeting all these requirements 21 , 22 . So far, the C signal has been combined for multivariate sensing with some others like volume, capacitance, work function, optical, and mass (Supplementary Table 1 ) 23 – 30 . Nevertheless, the counterpart transducers are often associated with high cost, limited applicability, and/or complexity.…”