Abstract: Wearable technologies for personalized monitoring require sensors that track biomarkers often present at low levels. Cortisol—a key stress biomarker—is present in sweat at low nanomolar concentrations. Previous wearable sensing systems are limited to analytes in the micromolar-millimolar ranges. To overcome these and other limitations, the present embodiments include a flexible field-effect transistor (FET) biosensor array that exploits a new cortisol aptamer coupled to nanometer-thin-film In2O3 FETs. Cortisol levels were determined via molecular recognition by aptamers where binding was transduced to electrical signals on FETs. The physiological relevance of cortisol as a stress biomarker was demonstrated by tracking salivary cortisol levels in participants in a Trier Social Stress Test and establishing correlations between cortisol in diurnal saliva and sweat samples.

Abstract: Example implementations include a method of applying a voltage pulse having a magnitude within a biochemical voltage window associated a biochemical, obtaining a response current from a biochemical sensor electrode, generating a biochemical response voltammogram based on the response current, extracting a current peak from the biochemical response voltammogram, and generating a biochemical concentration based on the current peak. Example implementations further include a method of applying a differential pulse sequence including the voltage pulse to the reference electrode. Example implementations further include a method of applying the differential pulse sequence further comprises applying the differential pulse sequence to the reference electrode at an increasing voltage step.

Abstract: Example implementations include a method of manufacturing a biochemical sensor by forming a fluid conduit in a microfluidic layer, forming an electrode on an electrode layer, forming a biochemical sensor on the electrode layer, bonding the electrode layer to a first surface of the microfluidic layer, and bonding a barrier layer to a second surface of the microfluidic layer. Example implementations also include a method of electrically detecting a biochemical by contacting an electrode array to a biological surface, obtaining a biofluid at the electrode array from the biological surface, obtaining a response current associated with the biofluid at the electrode array, and generating a quantitative biochemical response based at least partially on the response current. Example implementations further include applying a current to the biological surface. Example implementations further include filtering electrical interference at the electrode array.

Abstract: An electronically-controlled digital ferrofluidic device is disclosed which employs a network of individually addressable coils in conjunction with one or more movable permanent magnets, where each moveable permanent magnet delivers the designated fluid manipulation-based tasks. The underlying mechanism facilitating fluidic operations is realized by addressable electromagnetic actuation of miniaturized mobile magnets that exert localized magnetic body forces on droplets filled with magnetic nanoparticles. The reconfigurable, contactless, and non-interfering magnetic-field operation properties of the underlying actuation mechanism allow for the integration of passive and active components to implement advanced and diverse operations with high efficiency (e.g., droplet sorting, dispensing, generation, merging, mixing, filtering, and analysis).

Abstract: Example implementations also include a method of sensing the presence and quantity of a biochemical by applying a current across a biochemical sensing electrode and a reference electrode, contacting a hydrogel layer to a biological surface, absorbing a biofluid from the biological surface into the hydrogel layer, obtaining, at a processor coupled to the biochemical sensing electrode and the reference electrode, a change in current across the biochemical sensing electrode and the reference electrode, and generating, at the processor, a quantitative biochemical response. Example implementations further include obtaining a biometric encryption key based on the biological surface, and encrypting the quantitative response based on a biometric encryption key.

Abstract: Active biofluid management may be advantageous to the realization of wearable bioanalytical platforms that can autonomously provide frequent, real-time, and accurate measures of biomarkers in epidermally-retrievable biofluids (e.g., sweat). Accordingly, exemplary implementations include a programmable epidermal microfluidic valving system capable of biofluid sampling, routing, and compartmentalization for biomarker analysis. An exemplary system includes a network of individually-addressable microheater-controlled thermo-responsive hydrogel valves, augmented with a pressure regulation mechanism to accommodate pressure built-up, when interfacing sweat glands. The active biofluid control achieved by this system may be harnessed to create unprecedented wearable bioanalytical capabilities at both the sensor level (decoupling the confounding influence of flow rate variability on sensor response) and the system level (facilitating context-based sensor selection/protection).

Abstract: Example implementations include a device with an electrode electrically responsive to presence of a biochemical present within a biofluid, and one or more biofouling and interferent mitigation layers disposed on the electrode to block transmission of biofouling agents to the electrode and the reaction of interferents on the electrode. Example implementations also include a method of obtaining a biofluid sample, mitigating a biofouling characteristic associated with the biofluid sample, and obtaining a biochemical characteristic associated with the biofluid sample.

Abstract: A wearable device for biofluid analysis includes a set of sensing electrodes, and the set of sensing electrodes includes a working electrode which includes: (1) abase electrode including a sensing surface; (2) capture probes immobilized on the sensing surface; and (3) a protective layer e disposed on the sensing surface and including a redox couple within the protective layer.

Abstract: A disposable sensor for biofluid analysis includes: (1) a conductive film having a first major surface and a second major surface opposite to the first major surface; (2) a sensing layer disposed on the first major surface of the conductive film; and (3) an adhesive layer disposed on the second major surface of the conductive film.

Abstract: Example implementations include a method of manufacturing a biochemical sensor by forming a fluid region in a microfluidic layer, forming a reference electrode on a planar surface of an electrode layer, forming a biochemical sensor electrode on the planar surface, forming a selective membrane on the biochemical sensor electrode, forming an enzymatic material including a biochemical sensing material on the selective membrane, and bonding the electrode layer to the microfluidic layer. Example implementations also include a device with a reference electrode disposed on a planar surface of an electrode layer, a biochemical sensor electrode disposed on the planar surface, a selective membrane disposed on the biochemical sensor electrode and impermeable to at least one biochemical interferent, and an enzymatic layer disposed on the selective membrane and electrically responsive to a biochemical.

Abstract: A device for sweat analysis includes: (1) a sensing module configured to induce sweat and generate a sensing signal responsive to a sweat concentration of a target analyte in induced sweat, the sensing module including a calibrating sensor to generate a calibration signal responsive to a secretion rate of the induced sweat; and (2) a processor connected to the sensing module, the processor configured to derive a measurement of the sweat concentration of the target analyte from the sensing signal, and to derive a normalized measurement of a blood concentration of the target analyte from the calibration signal.

Abstract: A device for biofluid processing and analysis includes a microfluidic module including multiple stacked layers, each layer of the stacked layers defines a respective conduit, and conduits of the stacked layers are interconnected to provide a flow path for a biofluid.

Abstract: 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.

Abstract: Embodiments of the present disclosure provide for systems of enhancing the signal to noise ratio, methods of orienting a nanomaterial (e.g., an antibody), methods of enhancing the signal to noise ratio in a system (e.g., an assay system), and the like.

Abstract: A wearable sensing platform includes sensors and circuits to sense aspects of a user's state by analyzing bodily fluids, such as sweat and/or urine, and a user's temperature. A sensor array senses a plurality of different body fluid analytes, optionally at the same time. A signal conditioner is coupled to the sensor array. The signal conditioner conditions sensor signals. An interface is configured to transmit information corresponding to the conditioned sensor signals to a remote computing device. The wearable sensing platform may include a flexible printed circuit board to enable the wearable sensing platform, or a portion thereof, to conform to a portion of the user's body.

Abstract: The procedure of dielectric electrophoresis (dielectrophoresis or DEP) utilizes field-polarized particles that move under the application of positive (attractive) and/or negative (repulsive) applied forces. This invention uses negative dielectric electrophoresis (negative dielectrophoresis or nDEP) within a microchannel separation apparatus to make particles move (detached) or remain stationary (attached). In an embodiment of the present invention, the nDEP force generated was strong enough to detach Ag-Ab (antigen-antibody) bonds, which are in the order of 400 pN (piconewtons) while maintaining the integrity of the system components.

Abstract: A device for on-demand sweat extraction and analysis is realized as a printed circuit comprising a microcontroller, an iontophoresis circuit, a sensing circuit, and an electrode array having iontophoresis electrodes for sweat induction and sensing electrodes connected for sweat sensing. The sensing electrodes are positioned between the iontophoresis electrodes. The iontophoresis electrodes are preferably crescent-shaped and comprise a layer of agonist agent hydrogel loaded with sweat stimulating compounds. The iontophoresis circuit has a programmable current source for iontophoresis current delivery, and the sensing circuit includes two signal conditioning paths, where each of the paths includes an analog front-end to amplify a sensed signal and a low-pass filter to minimize high frequency noise and electromagnetic interference. The iontophoresis circuit and the sensing circuit are electrically decoupled for independent functionality.

Abstract: Embodiments of the present disclosure provide for systems of enhancing the signal to noise ratio, methods of orienting a nanomaterial (e.g., an antibody), methods of enhancing the signal to noise ratio in a system (e.g., an assay system), and the like.

Abstract: The procedure of dielectric electrophoresis (dielectrophoresis or DEP) utilizes field-polarized particles that move under the application of positive (attractive) and/or negative (repulsive) applied forces. This invention uses negative dielectric electrophoresis (negative dielectrophoresis or nDEP) within a microchannel separation apparatus to make particles move (detached) or remain stationary (attached). In an embodiment of the present invention, the nDEP force generated was strong enough to detach Ag-Ab (antigen-antibody) bonds, which are in the order of 400 pN (piconewtons) while maintaining the integrity of the system components.