| abstract |
A chemical sensor comprises a permeable freestanding nanoparticle composite material 3. A signal caused by a change of elastic modulus or pre-stress of material 3 is measured. The material may be suspended as a cantilever, beam or membrane over microcavity 6. Nanoparticles may be metal, metal oxide, semiconductor, carbon, metal dichalcogenide, core-shell, or Janus-type. A matrix of the composite may comprise organic polymers, polysiloxanes, organic ligands, or organic cross-linkers. A structural change or deformation of material 3 may be measured optically. Resistance, impedance, capacitance, spectral absorbance, reflectance or emission may be measured. Response to a static actuating force, or change in frequency, amplitude or phase in response to a dynamic force may be measured. Analyte concentration may be determined, after calibration. Analytes may be recognised from signal shapes. An array of sensors may be provided, and the sensor may be combined with sensors of other type. |