Technology demonstrations

An early technology demonstration was shown in the Prinse 20 seminar end of January at VTT in Oulu Finland. There the Imec Museic evaluation board was connected with printed electrodes in the targeted patch form factor to measure ECG in wrist. The result is shown in Figure 1.

Figure 1: ECG sensing demonstration using printed electrodes and the Imec Museic evaluation board.

The next version of technology demonstrations for skin patches will utilize several functional layers integrated as a vertical stack structure as schematically illustrated in Figure 2.

Figure 2: Skin patch layer structure under development.

Vias on stretchable substrate

Printing multi-layered electronics on stretchable or flexible substrates needs a solution to fabricate electrically conducting vias from one layer to another through the substrates. VTT has developed a reliable via printing process on stretchable TPU substrate. Scientific manuscript is under preparation.

Charging of printed Lithium-Ion-Battery by perovskite solar cell

In order to create fully independent product without need for any external charger and external connectors, the battery is connected with a state-of-the-art perovskite module which has enough output voltage for charging the battery outside and also at indoor light conditions. The perovskite module is built onto flexible PET substrate and has round shape in order to be compatible for integrated with all other elements of the final product. In picture below, the processing steps, top and cross-section views and electrical performance are demonstrated of flexible PSC module created for BEWELL project at IMEC.

Powered by printed Lithium-Ion-Battery LIB

LIB were developed based on the BASMATI layout FP7, Contract No. 646159.

LIB Test cell in BASMASTI format

LIB Test cell in BASMASTI format

The big advantage of the research in BEWELL is a new quasi solid electrolyte, based on the PEO/LiTFSI system. This electrolyte warranties high mechanical stability and good cycle-ability. The EIS diagram of the cell is shown below

EIS diagram of the printed LIB cell

EIS diagram of the printed LIB cell

Also, a good cycle-ability could be shown.

Cycling diagram of the LIB test cell

Cycling diagram of the LIB test cell

This result is very encouraging. In the course of the project the electrolyte will be improved in terms of internal resistance and printability.

Wellbeing Patch by Beiersdorf

Generation 0 was used to measure electrocardiogram (ECG) signal and compared to standard lab equipment. Following a period of rest, the heart rate was raised through exercise on a stationary bike and once again brought to rest.

These are promising results which will be further improved in next generation designs where the electrode spacing is increased and the electrode configuration is optimized.

Wellbeing Patch by Swarovski

For the Swarovski use case the overall electronics stack has been defined in detail, including the first approaches for integration processes. The Smart Wellbeing Patch structure includes:

  • Functional Decorative Layer, incl.:
    • Swarovski Functional Crystals (e.g. energy-harvesting crystals, touch-conductive crystals)
    • LED display layer
    • Perovskite Printed Solar Cell (PSC),
  • Electronics Layer (incl. for instance MUSEIC chip from IMEC + temperature, humidity and UV sensor),
  • Printed PVDF haptics element,
  • Skin-Adhesion Layer.

Swarovski Crystal with red LED backlight through blue color coating (left: switch off, right: switched on)

Currently first integration test runs for a demonstrator (generation 0) are conducted for the overall Smart Patch system.

Sport Wristband Device by Polar

For the POLAR use case a design was defined, consisting of different modules in a bracelet which are connected and work together as a monitor. Beside different modules the outer sides show Solar Cells (SC) and a display (MLCD) while the inner sides show Haptic elements (HAP1/2) for communication by vibration and PPG measurement interfaces (OHR). All electronics (including MCU, memory, RF transceiver and battery) are assembled on Flexible Printed Circuit. Other technologies are possible to use also like printed electronics or textile wires for interconnections.