A dual-mode epidermal sensor/electrode that, when worn on a human chest, is capable of synchronously/continuously monitoring electrical activity and mechano-acoustic activity of a cardiovascular system. The dual-mode epidermal sensor/electrode consists of a pair of stretchable electrocardiogram (ECG) electrodes made out of filamentary serpentine gold nano-membranes and a stretchable seismocardiogram (SCG) sensor comprising a filamentary serpentine PVDF. The dual-mode epidermal sensor/electrode is light, thin, flexible, and requires no operational power. The sensor can be laminated conformably and unobtrusively on a human chest to provide high fidelity ECG measurements and SCG measurements, and an estimated beat-to-beat blood pressure (BP). The dual-mode epidermal sensor is fabricated using a cost-effective, cut-and-paste method of construction.