A non-invasive epidermal electrochemical sensor device includes an adhesive membrane; a flexible or stretchable substrate disposed over the adhesive membrane; and an anodic electrode assembly disposed over the flexible or stretchable substrate including an iontophoretic electrode. The device includes a cathodic electrode assembly disposed adjacent to the anodic electrode assembly over the flexible or stretchable substrate and includes an iontophoretic electrode. Either the cathodic electrode assembly or the anodic electrode assembly also includes a sensing electrode that includes a working electrode and at least one of a counter electrode or a reference electrode. The iontophoretic electrode in either the anodic electrode assembly or the cathodic electrode assembly that includes the sensing electrode is disposed on the substrate to at least partially encompass the working electrode and the at least one of the counter electrode or the reference electrode. The device includes an electrode interface assembly including independent electrically conductive contacts.

Examples of the disclosure relate to an apparatus for sensing biometric parameters. The apparatus may comprise heat transfer means configured to transfer heat from a first location to a location proximate to a subject's sweat glands. The apparatus may also comprise sweat transfer means configured to transfer sweat from the location proximate to a subject's sweat glands to one or more sensors wherein the one or more sensors are configured to sense one or more biometric parameters from the subject's sweat.

A wearable device for multiplexed sweat analysis includes a sensing module. The sensing module includes multiple compartments, including a first compartment configured to induce sweat and sense a target analyte, and a second compartment configured to induce sweat and sense the target analyte.

The disclosed invention provides a sweat sensing device configured with self-aligned sweat stimulation means to provide adequate sweat generation for continuous monitoring of sweat. The disclosed device includes one or more analyte-specific sweat sensors that self-align with sweat glands. In one embodiment, the sweat sensing device includes means to protect the self-aligning sensors from abrasion against the skin or device components. In another embodiment, the device includes prolonged sweat stimulation for the self-aligning sensors through diffusion of a sweat stimulating compound into the skin.

Devices and methods for tuning biofluid sample pH to enable more accurate analyte concentration measurements with pH-sensitive biosensors. In the embodiments, biofluid samples react with a polymer buffering material during transfer to a sensing element. The reaction with the buffering material causes protonation or deprotonation of the sample based upon 1) the pH of the sample, and 2) the selected quantity and pKa of the functional groups in the buffering material. Controlling the H+ content of a biofluid sample has beneficial effects on the accuracy of the biosensor by reducing or eliminating signal changes due to redox moiety variability, thereby isolating signal changes reflecting analyte concentration.

The present invention provides a biofluid sensing device capable of concentrating a biofluid sample with respect to a target analyte, so that the analyte can be accurately detected or measured by EAB sensors. Methods for using such a device provide qualitative information about the presence of the analyte, and/or quantitative information about relative concentrations of the analyte in the biofluid. The disclosed device includes a concentration channel for concentrating the biofluid sample, as well as a selectively permeable membrane, one or more EAB sensors, and one or more secondary sensors carried on a water-impermeable substrate. A method for using the disclosed device to collect a biofluid sample, concentrate the sample relative to a target analyte, and measure the target analyte is also disclosed.

The disclosed invention provides sweat sensing devices with smart sweat stimulation and sensing embodiments: which improve the dependability and predictability of sweat sampling rates; achieve a desired number of sweat sampling events per day while minimizing skin irritation and prolonging device lifespan; and use physical, optical or thermal sweat stimulation to augment or replace chemical sweat stimulation.

The disclosed invention provides a fluid sensing device capable of collecting a biofluid sample, such as interstitial fluid, blood, sweat, or saliva, concentrating the sample with respect to a target analyte, and measuring the target analyte in the concentrated sample. Embodiments of the invention can also determine the change in molarity of the fluid sample with respect to the target analyte, as the sample is concentrated by the device. Some embodiments of the disclosed invention provide a fluid sensing device comprising minimally invasive, microneedle-enabled extraction of interstitial fluid or other biofluid for continuous or prolonged on-body monitoring of biomarkers. Some embodiments allow the collection and measurement of analytes in of non-biological fluids, such as fuels, or bodies of water.

A sweat sensor device (400c) for sensing sweat on the skin (12) includes one or more sweat sensors (420) and a volume-reducing component that provides a volume-reduced pathway (480) for sweat between the one or more sweat sensors (420) and sweat glands in said skin (12) when the device (400c) is positioned on said skin (12). The volume-reducing component may include a volume-reducing material (470) and a pressure-permeated component (460), a sweat dissolvable material (490), a mechanically compliant material (570) for conforming to the skin (12), an adhesive with a vertically anisotropic sweat pathway, and microcapsules (1385) including a barrier material. The presence of a volume-reducing component reduces the sweat volume and decreases the sampling interval.

The disclosed invention provides a sensing device capable of concentrating a fluid sample with respect to a target analyte and a reference analyte, and measuring the target analyte and reference analyte in the concentrated sample. The invention includes a concentrator that may include a selectively permeable membrane, or a gel having an increasing density gradient. In another embodiment, the invention includes an air or gas gap between a fluid transport channel and the concentrator. In another embodiment, the sensing device includes a driver for electronically moving a fluid sample through the channel and membrane to cause concentration. In some embodiments, the invention may also determine the change in molarity of the fluid sample with respect to the target analyte, as the sample is concentrated by the device.