Abstract: A gas sensor has a first aqueous phase. The aqueous phase is composed of a soluble dye in a buffer. One or more additional agent can be further added to the aqueous phase as for instance an emulisification enhancement agent. The aqueous phase is homogenized into a polymeric precursor forming a emulsion of the aqueous phase in the polymeric precursor. A catalyst and a cross-linking agent are added and the polymeric precursor material allowed to polymerize to form an emulsoid of micro-compartments of the aqueous phase in a polymeric second phase. The micro-compartments of the aqueous phase are dispersed through and permanently suspended in the polymeric second phase.

Abstract: A micro pH sensor is constructed by reacting powdered aminoalkylated cellulose with a dye to covalently bond the dye to the aminoalkyl groups on the cellulose. Any excess unreacted aminoalkyl groups are blocked with a blocking agent and the dye containing powdered cellulose is taken up in a solvent. A portion of the solvated dye containing cellulose is deposited in association with an optical fiber. The cellulose is regenerated into a solid matrix by acid treatment of the solvated dye containing cellulose to deposit the dye containing cellulose matrix on the optical fiber.

Abstract: An apparatus for sensing characteristics of a substance, such as blood, including a membrane support having first and second recesses and first and second dissimilar membranes extending over the first and second recesses, respectively. The membrane support has a groove between the recesses, and edge portions of the membranes extend into the groove on the side thereof adjacent the first recess. A retaining bar is received within the groove, and the membranes are tightly held between the retaining bar and the wall of the groove to form a smooth, essentially continuous surface. The membrane support forms a portion of a flow passage so that blood can flow along the membranes. First and second sensors are mounted on the sides of the first and second membranes opposite the flow passage for sensing characteristics of the blood. The first and second sensors engage the first and second membranes, respectively, to tension the membranes.

Abstract: An apparatus for sensing characteristics of a substance, such as blood, including a membrane support having first and second recesses and first and second dissimilar membranes extending over the first and second recesses, respectively. The membrane support has a groove between the recesses, and edge portions of the membranes extend into the groove on the side thereof adjacent the first recess. A retaining bar is received within the groove, and the membranes are tightly held between the retaining bar and the wall of the groove to form a smooth, essentially continuous surface. The membrane support forms a portion of a flow passage so that blood can flow along the membranes. First and second sensors are mounted on the sides of the first and second membranes opposite the flow passage for sensing characteristics of the blood. The first and second sensors engage the first and second membranes, respectively, to tension the membranes.

Abstract: An optical sensor comprising a selectively permeable matrix of hydrophobic material and a plurality of hydrophilic beads dispersed in the matrix. At least some of the beads carry an optical indicator. The matrix is capable of transmitting light at least at selected wavelengths from outside the matrix to the beads.