The present invention discloses a type of nanostructured ceramic platform for gas sensors and sensor arrays. These sensors comprise micromachined anodic aluminum oxide films, which contains extremely high density (e.g., 10.sup.11 cm.sup.-2) nanoscale pores. Sensing materials deposited inside this self-organized network of nanopores have ultra-high surface area and nanometer grain structure, therefore enabling high sensitivity. Refractory nature of alumina ceramic enables the desired robustness, long lifetime and stability in harsh environment. This sensor platform can been used for both chemical gas and physical (humidity, temperature) sensors and sensor arrays.

Methods of monitoring environmental variables in general and chemical composition in particular, and sensors for such monitoring. These low-cost sensors comprised multiple layers in a laminated stack. Very high numbers of sensing layers (e.g., 500) may be incorporated into a single laminated sensor device. The sensors may signal changes in environmental state such as chemical composition due to changes in sensor properties such as resistivity, capacitance, inductance, permittivity, permeability, refractive index, chromaticity, transparency to light, reflection characteristics, resonance frequency, and/or magnetic characteristics.

A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO.sub.3 particles doped with an element selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by plasma spraying doped LaCrO.sub.3 powder, preferably compensated with chromium as Cr.sub.2 O.sub.3 and/or dopant element, preferably by plasma arc spraying; and, (C) heating the doped and compensated LaCrO.sub.3 layer to about 1100.degree. C. to 1300.degree. C. to provide a dense, substantially gas-tight, substantially hydration-free, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the unselected portion of the air electrode, and a fuel electrode can be applied to the solid electrolyte, to provide an electrochemical cell.

A pigment prepared using nanofillers with modified properties because of the powder size being below 100 nanometers. Blue, yellow and brown pigments are illustrated. Nanoscale coated, un-coated, nanorods type fillers are included. The pigment nanopowders taught comprise one or more elements from the group actinium, antimony, aluminum, arsenic, barium, beryllium, bismuth, cadmium, calcium, cerium, cesium, cobalt, copper, dysprosium, erbium, europium, gadolinium, gallium, gold, hafnium, hydrogen, indium, iridium, iron, lanthanum, lithium, magnesium, manganese, mendelevium, mercury, molybdenum, neodymium, neptunium, nickel, niobium, nitrogen, oxygen, osmium, palladium, platinum, potassium, praseodymium, promethium, protactinium, rhenium, rubidium, scandium, silver, sodium, strontium, sulfur, selenium, tantalum, terbium, thallium, thorium, tin, titanium, tungsten, vanadium, ytterbium, yttrium, zinc, and zirconium.

Size-confined nanocomposite powders and methods for their manufacture are provided by coating fine powders with a nanoscale powder of a different composition. The nanocomposite plastics offer performance characteristics approaching those of metals and alloys. The nanocomposite powders are alternatively used for dispersion strengthening of metals, alloys, and ceramics. Materials based nanotechnology for energy devices and programmable drug delivery are included.