Provided herein are epidermal microfluidic systems and methods that allow for the collection of biofluids in a wet or aquatic environment, for example, from the surface of the skin. The described systems allow for the efficient collection of biofluids, without loss of the biofluid to the surrounding environment or introduction of extraneous liquids from the environment. The described microfluidic systems are versatile and can provide information regarding a number of biofluid properties both electronically and colorimetrically/visually.

A sweat collection device includes a flexible body having a first, outwardly facing surface and a second, skin-facing surface, and a sweat collection channel formed in the body, the sweat collection channel having a first end defining a sweat inlet port, and a second end defining a sweat outlet port. The sweat inlet port and the sweat outlet port are configured to be closed and sealed such that the sweat collection device and the collected sweat therein may be stored and shipped.

A device is able to be used to detect an illness and/or symptoms of the illness in a user by utilizing a body fluid detector and/or other devices. The device is also able to determine when additional devices of users come within a specified distance of the device. An alert regarding a diagnosis and/or analysis of the symptoms of the illness is able to sent to a central server, a cloud device or another device to share the diagnosis and/or the analysis of the symptoms of the illness with the additional devices of users.

Described herein is an amperometric biosensor, e.g., chronoamperometric biosensor for the measurement of the concentration of nicotine. Also disclosed herein is a wearable nicotine biosensor device and a biosensor that detects nicotine in smoke. The biosensor disclosed herein comprises a nicotine-catalyzing enzyme, such as NicA2 or mutant NicA2 enzymes. Also described herein are systems comprising said amperometric biosensor, e.g., chronoamperometric biosensor and methods of using said chronoamperometric biosensor.

Methods, systems, and devices are described herein for various embodiments of using a sample analysis system to analyze a sample of bodily fluid from a user to determine parameters associated with the user including states of hydration, dehydration, rehydration, electrolyte loss, wellness, recovery, and the like. In some embodiments, the methods disclosed can be implemented using a device worn by a user, and operatively coupled to a sample analysis system configured to collect a sample of bodily fluid, and measure and analyze the bodily fluid to determine a property of the bodily fluid and/or a physiological/wellness parameter (e.g., degree of hydration, electrolyte losses, perspiration rate, etc.) of the user.

A wearable device for determining risk of an underlying health concern is disclosed. The wearable device comprises a replaceable medium for absorbing perspiration of a user, wherein the replaceable medium is at least occasionally in contact with the user. The device also includes a power source electrically connected to the medium, and a resistance detector processor for periodically detecting the electrical resistance of the absorbed perspiration, wherein the electrical resistance of the absorbed perspiration is dependent on the salinity of the perspiration. Further, the device includes a risk detector processor for: (1) determining whether the detected resistance meets at least one condition, and (2) triggering an alert signal if the at least one condition is met, a storage device for storing resistance values; and a warning signal generator for providing a warning signal to the user based on the alert signal.

A system for transdermal alcohol sensing to be worn near a skin surface of a user, including: an alcohol sensor; a microporous membrane; a housing coupled to the alcohol sensor and the membrane, defining a volume between the alcohol sensor and a first membrane side, and fluidly isolating the volume from a second membrane side opposing the first membrane side; an electronics subsystem electrically coupled to the alcohol sensor, operable to power and receive signals from the alcohol sensor; and a fastener operable to position the second membrane side proximal the skin surface.

The invention provides a versatile sensing platform for sensing and analysis of biofluids, particularly well-suited for sensing and analysis of sweat. Systems of the invention allows for sensitive and selective detection of a range of analytes in sweat including metabolites, electrolytes and biomarkers. Systems of the invention provide a noninvasive and accurate means for quantitative characterization of important sweat characteristics including sweat volume, sweat loss and sweat rate. Systems of the invention are compatible with materials and device geometries for important class of conformal tissue mounted electronic devices, including epidermal electronic devices.

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.

A device is able to be used to detect an illness and/or symptoms of the illness in a user by utilizing a body fluid detector and/or other devices. The device is also able to determine when additional devices of users come within a specified distance of the device. An alert regarding a diagnosis and/or analysis of the symptoms of the illness is able to sent to a central server, a cloud device or another device to share the diagnosis and/or the analysis of the symptoms of the illness with the additional devices of users.