Introduction

The invention describes a method to fabricate a breathable electronic tattoo, to be used as a biomedical monitoring device. The tattoo can be applied onto the patient’s skin (or on a robotic body for applications in robotic) in such a way to be fully imperceptible and to allow detection of biomedical parameters as biopotentials or biochemical/biophysical signals. The invention is at an advanced development phase: TRL 4.

Technical features

The invention consists of a technique, consisting of 5 phases, for the fabrication of electronic devices on top of ultra-thin polymeric substrates for applications in the biomedical field, for the detection of biopotentials (EMG, ECG, EEG, EOG) and other physical and chemical parameters (e.g. pH and T). The technique is compatible with the common methods of electronic fabrication (standard photolithography, ink jet or screen printing, micro-contact printing, roll-to-roll techniques) and allows obtaining ultra-thin sensorized patches with high breathability, biocompatibility, conformability (i.e. perfect adhesion to whatever substrate, skin or 3D surfaces).

Charging, in case the tattoo contains only passive electrodes, is not necessary. Instead, it is necessary to take the signal and possibly process it and transmit it. The patent takes into account that these operations are carried out through an electronic module on a flexible substrate that is “hooked” to the tattoo in its thickest part (part of the patent is dedicated to the fact that the tattoo is of varying thickness; being very thin in the part that houses the measuring electrodes, and thicker in the part that interfaces with the flexible electronic module). This same electronic module could house the power supply in the event that we decide to put an active device on the surface that performs the measurements, or that needs power. Therefore, we could put “power supply via NFC protocol” or “via cables and magnetic connectors”. In fact, submicron thick sensorized breathable patches have been developed and tested for EMG (passive electrodes) and tactile applications (pressure and temperature sensors based on organic field effect devices).

Possible Applications

• Biomedical sector: detection of biopotentials in standard hospital conditions or medium/long term monitoring (Holter-like);
• Rehabilitation and sport;
• Robotics.

Advantages

• Sub-micron thickness of the substrate;
• Imperceptible devices;
• Breathability;
• Compatible with common fabrication techniques.