We’re a little closer to getting rid of bulky health sensors now that scientists have created a super-thin wearable that can record data through skin. That would make this wearable, which looks like a stylish gold tattoo, ideal for long-term medical monitoring — it’s already so comfortable that people forgot they were wearing it.

Most skin-based interfaces consist of electronics embedded in a substance, like plastic, that is then stuck onto the skin. Problem is, the plastic is often rigid or it doesn’t let you move and sweat. In a paper published today in the journal Nature Nanotechnology, scientists used a material that dissolves under water, leaving the electronic part directly on the skin and comfortable to bend and wear. Twenty participants wore it on their skin for a week without problems. They didn’t get itchy or irritated, and the wearable didn’t break.

There’s been a lot of interest in skin-based interfaces that remotely control a phone or turning skin into a touchscreen for a smartwatch. Those are cool tricks, but health monitoring is higher priority. Almost all kinds of medical monitoring — from measuring brain signals or heart beats — means putting electrodes on the skin. This is fine for the lab, but not convenient if you need to continually monitor these vital signals at home.

This new system uses a mesh made of a material called polyvinyl alcohol that’s already used in contact lenses and artificial cartilage. First, the scientists used electrical force to created charged threads of the material. (This is called electrospinning.) These threads were coated in gold to make them more electrically conducive. You put the entire thing on skin — in this case, the hand — and spray on some water. The polyvinyl alcohol disappears, but the gold threads are still there, and it can be used to power a LED light, or transmit data to a laptop.

There’s a lot of potential here, but the downside of the sensor being so comfortable is that it’s also delicate and might not be durable enough for the long-term. So you win some, you lose some — but having gold electronics right on the skin sure beats heavy straps or ugly caps.