Kickstarter · from the makers of BioSenseAir

Nobody knows what
healthy skin gas
actually looks like.

Your skin is constantly emitting acetone, ammonia, aldehydes and CO₂. Researchers have measured these compounds one lab study at a time, on a few dozen people each. There is no open baseline dataset. SkinSenseAir is a wrist-worn instrument that measures your skin's emissions alongside your heart rate and your environment — and 1,000 of us are going to build that baseline together.

Fig. 1 — 1,000 overlaid recordings. One is yours. tracing…
17On-device screens
42CSV columns per sample
1,000Early-bird rings included
$199Early bird · retail $279
Watch

Five films, five questions.

We would rather show you the instrument working than tell you it does.

The point of 1,000

One person's skin gas is noise.
A thousand is a dataset.

This is the honest reason to back this project. A single reading from a single wrist tells you almost nothing — there is no published range to compare it against. But 1,000 instruments running the same sensors, the same firmware and the same 42-column schema, in different climates and on different bodies, produces something that does not currently exist: an open, pooled baseline of human skin emissions with environmental and biometric context attached.

Step 01

You record

Seal the chamber against your forearm, pick an activity, press start. Skin gas, chamber climate, heart rate, HRV, SpO₂, GPS and altitude are logged together every few seconds.

Step 02

You choose what to share

Contribution is opt-in and per-session. You pick each run individually. Location is coarsened to a 10 km grid before it leaves the device, and there is no account to create.

Step 03

The pool grows

Shared runs are aggregated into a public dataset, released under CC BY-SA. Anyone can download it. We are not selling it, and we are not the only ones who get to use it.

Step 04

Your readings gain a frame

Once there is a pool, your dashboard can finally answer "compared to what?" — showing where your run sits against the distribution instead of floating without reference.

The instrument

Built on the bench, not in a render.

Every photograph below is the actual hardware. Nothing here is a visualisation.

On the wrist

Worn position, strap fitted, screen live.

The sensor bay

SHT40, SGP40, STCC4, BME690 and the MiCS-6814 array, open and vented.

The sealed chamber

Silicone cup against the forearm, the part that makes a flux reading possible.

Ring and unit together

COLMI R02 on the finger, SkinSenseAir on the wrist, paired.

Route map on a phone

Waypoints coloured by CO₂, with heart rate at each point.

A day of raw CSV

42 columns, on the card, yours to take. No cloud lock-in.

The clock face

Analogue hands on the 1.47″ panel. Faces are JSON on the card.

Portrait and landscape

The same unit, four button presses apart. Both laid out separately.

VENT CHAMBER

The prompt that stops a saturated chamber quietly ruining a run.

On the wrist

Seventeen pages on the device.
No phone required.

The dashboard is the deep end. But most of the time you are on a walk, in a lab coat, or halfway through a session with one hand full — so the instrument has to be readable and operable on its own. Seventeen pages on a 1.47″ panel, driven entirely by one button.

🕐

Clock

01/17

An analogue dial with real hands, plus the date. The device has no RTC battery and, in field mode, no route to a time server — so the browser sets the clock the moment you open the dashboard, then corrects the drift every six hours.

  • Faces are JSON files on the SD card
  • Four included; write your own
  • Hold the button to cycle faces

Home & gases

02–04/17

The four numbers worth glancing at, in 48 pt type you can read at arm's length. The eight MiCS channels are split across two pages rather than crammed onto one.

  • CO, NH₃, NO₂, ethanol on the first
  • The cross-sensitivity channels on the second
  • Hold to capture a clean-air baseline
🎯

CO₂ flux & VOC

05–06/17

Two large arc gauges with the live figure beside them, and the chamber flux in ppm per minute — the one reading here that does not depend on how much ambient CO₂ was trapped when you sealed the cup.

  • Arm and disarm with a long press
  • Vent countdown when a reminder is set
  • BME690 gas resistance against baseline
🌡️

Climate & skin index

07–08/17

Skin temperature, chamber humidity, dew point and absolute humidity — the numbers you need to interpret everything else, because humidity is the dominant confounder in any metal-oxide reading. Then the five derived indices as bars.

  • Absolute humidity, not just %RH
  • Metabolic, ammonia, sulfur, oxidative, sweat
  • Relative and explicitly not clinical
💓

Trend & wearable

09–10/17

A fifteen-minute trace of any channel, and the ring's vitals on the device itself — heart rate, SpO₂, HRV and body temperature, without reaching for a phone.

  • Long-press to change the charted metric
  • Live link status, or how stale the data is
  • ECG capture from a paired watch
🌤️

Weather & route

11–12/17

Local conditions and your position, both sourced from the phone and pushed down to the unit — so the device shows them even when it is running as its own access point with no internet of its own.

  • Feels-like, wind, humidity, today's range
  • Says how old the reading is once it is stale
  • Position labelled live or demo, never ambiguous
🔋

Battery

13/17

Charge state on a proper lithium discharge curve rather than a straight line — because a straight line reads 35 % on a nearly flat pack and then sits at 100 % for the first half hour of a session.

  • Voltage, percentage and cell state
  • Runtime estimate from observed discharge
  • Shows dashes rather than inventing a number
💾

Card, system & analyst

14–17/17

Files on the card, network and IP, free memory, the run label, and the AI analyst's summary — all reachable without opening a browser.

  • Start and stop logging from the device
  • Change the ML run label in place
  • Analyse the last fifteen minutes on demand
One button

Everything, from a single press.

There is one button on the unit. Gloves, a lab coat pocket, a wrist strap under a sleeve — the fewer things to find, the better. So it counts.

Press

  • Once — next page
  • Twice — previous page
  • Three times — screen off and on
  • Four times — rotate the whole UI

Landscape or portrait, laid out separately rather than merely rotated — the type sizes and the page structure both change to suit the shape.

Hold

  • 0.8 s — the page's own action
  • 3 s — deep sleep, button wakes it
  • 6 s — power off, reset to restart

Both power states are previewed on screen while you hold, and nothing happens until you let go — so if you overshoot, keep holding and read what it says.

Vent reminder

  • Full-screen prompt, amber LED
  • Counts only during a measurement
  • Acknowledged with the same button

A sealed chamber saturates, and a saturated chamber reads as a falling metabolic rate rather than as a full box. This is the setting most likely to save a run.

Sleep on idle

  • Adjustable, 0 to 240 minutes
  • Counts from the last button press
  • A logging run always overrides it

A capture that stopped itself at minute ten would look like it had worked, which is worse than not running at all. So it never interrupts one.

The dashboard

Thirteen more, on your phone.

The device stands alone. But for the analysis that needs a bigger screen, the dashboard is served by the unit itself and opens in any browser — nothing to install, no account, and it keeps working if we disappear. Here is every screen and what it does.

Live

01/13

The screen you watch while a session runs. A four-pen strip-chart recorder scrolling the last 15 minutes, three analogue gauges with damped needles, and the sealed-chamber flux reading.

  • Arm the chamber and watch dCO₂/dt climb
  • Skin temperature, chamber humidity, dew point
  • Five derived skin indices as live bars
🫧

Gases

02/13

All eight MiCS-6814 gas equivalents at once, plus the raw sensor resistances underneath — which are the numbers that actually matter for machine learning.

  • CO, NO₂, NH₃, propane, butane, methane, H₂, ethanol
  • Raw reducing / oxidising / ammonia resistance
  • Capture a clean-air R0 baseline
📈

Trends

03/13

History for any channel over 5 minutes, 15 minutes, an hour, or the whole session, on a real clock axis rather than a sample count.

  • Auto-ranged chart with min, max, mean, σ
  • Ticks snap to clean clock boundaries
  • Drift per minute, so you can see baseline creep
💍

Ring

04/13

Your COLMI R02, read directly over standard Bluetooth profiles. Heart rate, HRV computed from RR intervals on-device, SpO₂, skin temperature, steps and ring battery.

  • 15-minute heart-rate trace
  • RMSSD HRV, not a vendor's proprietary score
  • Works with any standard BLE heart-rate device

Watch

05/13

Optional smartwatch support for people who already own one. Vitals, blood pressure estimate, respiration, stress index, and a single-lead ECG trace on proper ECG paper.

  • 30-second ECG capture, plotted on 1 mm grid
  • Enumerates the watch's GATT services
  • Marked clearly as not diagnostic
📶

Hub

06/13

Scan, identify and connect wearables. Devices are fingerprinted by name and by the Bluetooth services they advertise, so you can see what a device can actually provide before pairing it.

  • Signal strength and mapped metrics per device
  • Assign any device as ring or watch
  • Works through the unit's own radio, not the phone's
📡

GPS

07/13

Position from your phone's GNSS, with an honest readout of which positioning source is in use — because that determines whether you get altitude and speed at all.

  • Live map with accuracy circle and heading
  • Choose your waypoint cadence: 5 s to 60 s
  • Export the whole track as GPX
🗺️

Route

08/13

Your walk, coloured by any channel you choose. Tap any waypoint for every reading recorded at that moment — gas, biometrics and position together.

  • Ten basemaps including satellite and topo
  • Activity markers: walk, run, bike, car
  • Elevation profile from GNSS, barometer or terrain
💾

Card

09/13

Everything is written to the SD card as plain CSV. This screen manages it: browse by day, preview any file as a chart, download it, or delete it.

  • 42 columns per sample, no cloud required
  • A flag on every row marking synthesised values
  • Storage meter with days-remaining estimate
  • Preview any numeric column before exporting
🔬

Insights

10/13

The correlation matrix. Six biometrics against six gas channels, Pearson r, computed only where at least 30 samples line up within six seconds of each other.

  • Colour-coded matrix, direction and strength
  • Strongest relationships ranked with sample counts
  • Blank cells stay blank rather than guessing

Analyst

11/13

A conversation with Claude about your own data. It receives your window statistics, your correlations, your route and a built-in table of published skin-gas research.

  • Ask follow-up questions; it keeps context
  • Names the confounder before the mechanism
  • Your API key, stored on your device only
⚙️

Setup

12/13

Network, appearance, power and calibration. Join a router or run as a standalone access point — rename it, or lock it with a password — and set the run label that becomes your machine-learning target.

  • Screen orientation, brightness, auto-sleep
  • Vent reminder and battery capacity
  • Clock face picker and JSON editor
  • Clean-air R0 and BME690 baseline capture

Help

13/13

The protocol, written into the device. Burn-in, calibration, chamber materials, and a plain explanation of what each reading can and cannot tell you — including the parts that are estimates.

  • Every button gesture and all 17 device pages
  • Eight-step first-session walkthrough
  • Why humidity is the dominant confounder
  • Why venting matters more than any setting
First 1,000 backers

A smart ring is included, because the gas data needs a body attached to it.

Skin emissions move with perfusion, exertion and skin temperature. Without heart rate and HRV recorded at the same moment, you cannot tell a metabolic signal from someone simply walking faster. That is why the ring is bundled rather than sold as an upsell — the dataset is substantially weaker without it.

The first 1,000 units ship with a COLMI R02, chosen for one unglamorous reason: it speaks the standard Bluetooth heart-rate and pulse-oximeter profiles, so we can read it directly instead of going through a vendor cloud.

Included · first 1,000 only

COLMI R02 smart ring

  • HRContinuous heart rate, standard BLE 0x180D
  • HRVRMSSD computed on-device from RR intervals
  • SpO₂Pulse oximetry, standard BLE 0x1822
  • SleepStage estimates and resting baselines
  • BatteryAround 3 days per charge
  • SizingRing sizer posted to you before production
The AI Analyst

An analyst that argues with your data,
not one that flatters it.

Every SkinSenseAir has a built-in analyst powered by Claude. You can ask it anything about your session in plain language and it answers with your actual numbers — the window statistics, the correlations between your ring and your skin gas, your route, and a reference table of published skin-gas research that ships with the device.

Here is the part we are most proud of. The analyst is instructed to look for the boring explanation first. Humidity, movement, skin temperature and chamber accumulation will produce impressive-looking correlations all day long. The prompt requires it to name the confounder before it names a mechanism, and to say plainly when the hardware cannot support a conclusion. A tool that tells you what you want to hear is worse than no tool.

You My ammonia went up 40% on that walk. Is that real?
Claude Probably not, and here is why. Your chamber humidity rose 14 points over the same window, and the ammonia channel tracks it almost one to one — that is the classic humidity artefact on a metal-oxide film, not chemistry.

What makes it worth a second look is that skin genuinely is the better site for ammonia. Passive flux sampling across 13 body regions found 2.9 to 12 mg/h per person, which exceeds breath emission. So there is something real to detect here.

The test that separates them: walk the same route twice, once with the chamber sealed and once with a 2 mm vent. Accumulation and humidity both collapse with the vent. Anything that survives it is chemistry.

Real output from the shipping firmware. Your API key, your account, your data — we never see it.

Back the project

Two ways in.

Both tiers include the ring while the first 1,000 last. Both ship with the full CSV export, the open dashboard, and the STEP and OpenSCAD files for the case.

Early bird · 1,000 only

One unit + ring

$199Retail $279 · save $80
  • SkinSenseAir wrist unit, assembled and calibrated
  • COLMI R02 smart ring, sized to you
  • Two silicone sampling chambers
  • Wrist strap and USB-C cable
  • Lifetime firmware and dashboard updates
  • Named in the dataset contributors file, if you want to be
Pledge $199
— of 1,000 claimed
Best value

Two units + two rings

$349Retail $558 · save $209
  • Two complete SkinSenseAir units
  • Two COLMI R02 rings, sized individually
  • Four silicone sampling chambers
  • Paired-session mode: two people, one comparison
  • Free shipping worldwide
  • Both units counted separately in the dataset
Pledge $349
Unlimited · ships with wave one
Read this before you pledge

What SkinSenseAir is not

  • It is not a medical device. It does not diagnose, treat, monitor or screen for any condition, and it must not be used to make health decisions. If something about your health concerns you, see a clinician.
  • It cannot identify a specific compound. Metal-oxide sensors are broadband. Every gas name in the app is a datasheet curve applied to a channel, not a measurement of that molecule. Only the CO₂ reading is a true single-compound measurement.
  • Humidity is the dominant confounder. A sealed chamber against skin runs 60–95% relative humidity, and metal-oxide films respond to water. We correct for it, log it alongside everything else, and say so loudly — but it never fully goes away.
  • The dataset may not find anything. We think a pooled baseline is worth building whether or not it produces a headline result. If that is not a bet you want to make, this is not the project for you.

We would rather lose a pledge than overstate what this instrument does. That standard is the same one built into the AI Analyst.

Where we are

Working hardware, not a concept.

Done Firmware complete: 17 on-device pages in both orientations, one-button control, BLE wearable relay, 42-column CSV logging to card.
Done Phone dashboard: live traces, route mapping, correlation matrix and the AI Analyst.
Done Enclosure designed from the board CAD, printed and fitted.
Month 1–2 Design-for-manufacture pass, injection tooling quotes, ring sizing posted to backers.
Month 3 Pilot run of 50 units. Burn-in and calibration of every sensor array before shipping.
Month 4–5 Wave one ships. Dataset portal opens with the pilot recordings already in it.
Questions

The ones that actually get asked.

Do I have to share my data?

No. Contribution is opt-in per session, and the device is fully functional if you never share a single run. Everything logs to the card either way and the CSV is yours.

What exactly gets shared if I opt in?

The sensor columns, your activity label, and a location coarsened to a 10 km grid square. Not your name, not your address, not a precise track. There is no account.

Can I use a ring I already own?

If it exposes the standard Bluetooth heart-rate and pulse-oximeter profiles, yes — the firmware reads those directly. Oura is the notable exception: its Bluetooth link is encrypted and bound to their app, so it needs their cloud API instead.

Do I need my phone for it to be useful?

No. Seventeen pages on the device cover every reading, and one button starts a log, captures a baseline, arms a flux run and changes the ML label. The phone dashboard adds the deep analysis — correlation matrix, route map, AI analyst — plus two things the unit cannot get on its own: the clock, and local weather. Open the dashboard once and both are set.

What is the vent reminder, and why is it a headline feature?

Because it is the difference between data and confident nonsense. A sealed chamber saturates — gases accumulate against the emission gradient until the reading stops tracking what your skin is emitting and starts tracking what the cup has already collected. The flux flattens toward zero and looks exactly like a falling metabolic rate. Set an interval and the device prompts you to open the chamber; acknowledging it also disarms the flux run, because venting destroys the baseline it was measuring against.

Can I design my own clock face?

Yes, and it takes about a minute. A face is a small JSON file on the SD card describing colours, tick style and hand geometry — every key optional. Write it in the dashboard's text box and it saves straight to the card, or drop a file on the card directly. Four are included to start from. We chose a style file over image faces deliberately: images would need a decoder, a filesystem driver and a conversion step, for artwork most people would not change.

How long does the battery last, and how do I know?

The battery page shows charge on a real lithium discharge curve, not a straight line, and estimates remaining runtime from the drop it has actually observed. Be aware there is no current shunt on this board — the estimate is extrapolation, so it shows dashes for the first ten minutes rather than inventing a figure, and it is wrong right after a load change. You can also set an auto-sleep timer; it never interrupts a logging run.

Why does the CO₂ flux number matter more than the ppm?

Concentration in a sealed cup depends on how long it has been sealed. Emission rate does not. The flux figure is the one that means something physiologically.

Is the software open?

The dashboard, firmware and case files are published. The AI Analyst uses your own Anthropic API key, stored on your device — we never see your data or your key.

What if the campaign underdelivers?

The hardware works today; the risk is manufacturing, not invention. The realistic risks are tooling delays and sensor lead times, both of which we have quoted and budgeted for. Kickstarter is all-or-nothing, so you are not charged unless we fund.