Nano230

The morphologies and thickness of the PEDOT:PSS embedded stretchable conductor and the nano-patterned dielectrics were investigated by using a Nano 230 field-emission scanning electron microscope (FEI, USA) at an accelerating voltage of 10 kV. Optical transmission measurements of the stretchable conductors were performed on ultraviolet–visible spectrophotometer (Cary 5000, Agilent) from 400 to 800 nm. The sheet resistances (Rs) of the stretchable conductors were measured using the four-point van der Pauw method with collinear probes (0.5 cm spacing) connected to a four-point probing system (CMT2000N, AIT). For the electrical measurement of the strain sensor unit, an external shear force was applied by a commercial linear mechanical motor (X-LSM 100b, Zaber Technologies) and a programmable electrometer (Keithley model 6514) was used to measure the open-circuit voltage and short-circuit current. For the vibration sensor unit, a Digital Phosphor Oscilloscope (DPO 3052, Tektronix) was used to measure the electrical output signals at the sampling rate of 2.5 GS/s. For the multi-channel sensing system, a DAQ system (PCIe-6351, NI) was used to simultaneously measure electrical output signals of multi-channel sensor units.