A flexible dry electrode based on APTES-anchored PDMS substrate for portable ECG acquisition system

We developed a simple and low-cost flexible dry electrode with micro domes by depositing metal film directly on (3-aminopropyl)triethoxysilane (APTES)-anchored polydimethylsiloxane (PDMS) substrate for portable electrocardiogram (ECG) acquisition system. However, the adhesion between metal and PDMS was poor, and metal film on PDMS always exhibited wrinkles. To overcome these difficulties, before depositing Cu, PDMS substrate was treated by APTES aqueous solution. Then, we evaluated the metal film through the microscopic photographs, the surface roughness measurements and the adhesion tests. On the base of the deposition technique improvement, a PDMS-based dry electrode for ECG monitoring was fabricated. We studied the performance of the flexible dry electrode and the results showed the fabricated electrode produced good ECG signals with distinct P, QRS, and T waves. In addition, the fabricated flexible dry electrode with micro domes showed lower skin-contact impedance and could obtain ECG signals with higher SNR than the flat dry electrode.