Tracking fitness and health-related biometrics require users motivated to wear the devices. Blood alcohol content (BAC) sits in an interesting spot between health and fitness. BAC monitoring is unique in its safety and legal implications. Many people have wondered if they’re OK to drive or need to wait a while. No was ever arrested for driving with high blood pressure or heart rate variability. The chance of getting a DUI or DWI, especially for repeat offenders, may be sufficient to build a cross-generational market for wearable blood alcohol content sensors. We’ve looked at wearable BAC technologies previously, including tattoos, a personal breathalyzer, and BACTrack, a transdermal BAC sensing wristband.

Milo Sensors, Inc. is developing Proof, another transdermal blood alcohol content wristband but this one uses replaceable enzymatic electrochemical sensor cartridges. Alcohol molecules present in sweat are converted by the cartridge to electrical current that is amplified, digitized, and transmitted to an associated smartphone via Bluetooth wireless. The algorithm in the Proof app converts the electrical signal data into a blood alcohol content estimate. Depending on user-determined BAC limits, the smartphone sends an alert if the BAC reaches a limit. Milo Sensors launched an Indiegogo crowdfunding campaign for Proof that sold out in 15 days. First deliveries from the campaign are scheduled for December 2017. Unlike most fitness and health wearables, Proof uses consumable supplies in the form of disposable cartridges rated for 12-hour use. Prices have not been set for the Proof wristband or cartridges. During the crowdfunding campaign, however, a $59 Early Bird special included the wristband, a USB charger, and a 5-pack of disposable cartridges. Customers could also reserve an additional 10 cartridges for $20, so the nominal price may be around two dollars each.

Proof is not yet available. Milo Sensors has established a waitlist for future sales once it fulfills the orders from Indiegogo backers. Milo Sensors considers itself primarily a hardware company focused on analyzing biometric data from on a molecular level and has stated its interest in working with additional molecule types other than just alcohol in sweat.