Fig. 2. System architecture and fabrication of sleep monitoring devices.

(A) Specific locations of electrodes in the sleep patches for monitoring EEG, EOG, and EMG. Scale bar, 1 cm. (B) Diagram showing the sequence from physiological signal detection to Bluetooth (BLE) based wireless data transmission and processing with a deep learning algorithm. DAQ, data acquisition. ADC, analog to digital converter. SPI, serial peripheral interface. RF, radiofrequency. (C) Photo of a 7 × 9 array of nanomembrane electrodes fabricated via laser micromachining on a 5-inch glass capturing its scalable manufacturability. Scale bar, 1 cm. (D) Optical microscope image of an electrode in (C), showing open-mesh patterns. Scale bar, 1 mm. (E) Photo of four sets of stretchable copper interconnectors fabricated via laser micromachining on an 8 inch–by–10 inch glass. Scale bar, 2 cm. (F) Optical microscope image of interconnectors with the solderable contact pad for connecting electrodes and circuits. Scale bar, 1 mm. (G) Fabricated electrode integrated with a piece of soft fabric after transfer printing and connecting with a stretchable interconnector. (H) Demonstrated stretchability of the electrode in (G) by conformally wrapping around a 1-inch-diameter sphere. (I and J) Optical microscope images of a fabric-silicone adhesive composite enclosing the electrode, showing a top-view structure (I) and a cross-sectional view (J). The soft silicone adhesive penetrates through the networks of fabric fibers to achieve mechanical interlocking for robust integration of the bilayer. Scale bars, 3 mm.