Extended Data Fig. 3: Fabrication of PFPE-DMA-encapsulated stretchable mesh electronics.

a, b, Schematics showing the overlook (a) and section view (b) of the nitrogen chamber designed for use with the mask aligner in PFPE-DMA photopatterning. c, Schematic showing how the nitrogen chamber is used with mask aligner. d, Microscopic BF images showing representative high-resolution PFPE-DMA photolithography patterns made with the nitrogen chamber. e, f, Microscopic BF images showing the improved adhesion between Au interconnects and PFPE-DMA after inert gas plasma treatment. Dashed boxes highlight the sputtered regions on the PFPE-DMA layers. Without inert gas plasma treatment, Au interconnects peel off from the PFPE-DMA film after sputtering (e). With inert gas plasma treatment before sputtering, Au interconnects strongly bond to the PFPE-DMA film (f). g, Microscopic BF images showing the stretchable mesh electrode array region of PFPE-DMA device in fabrication steps corresponding to (Fig. 2c). Step 1 shows a homogeneous Ni layer. Step 2 is not included because the electrode array region does not have an SU-8 spacer. Step 3 shows Pt electrodes on the Ni layer. Electrodes are highlighted by red dashed circles. Steps 4-6 show sequential patterning of bottom PFPE-DMA, Au interconnects, and top PFPE-DMA layers. h, Schematics showing the post-fabrication steps of PFPE-DMA-encapsulated stretchable mesh electronics following (Fig. 2c). After fabrication, the device is soldered with a flexible flat cable (step 7) and bonded with a culture chamber (step 8). Then, the Ni layer is etched to release the device. Pt-black is electro-polymerized on electrodes to reduce electrode impedance. The device is washed with 0.1 × MMR and finally soaked in culture media (step 9).