Most biological tissues are supple and elastic,while current electronic devices fabricated by semiconductors and metals are usually stiff and brittle. As a result,implanted electronic devices can irritate and damage surrounding tissues,causing immune reaction and scarring. In this work,we develop stretchable microelectrode arrays,with the development of a novel soft lithography technology,which are designed and fabricated with a polymer/stretchable metal/polymer sandwich structure. With the great deformability of stretch,compression,bend and twisting,while preserving electrical property,this technology overcomes the fundamental mismatch of mechanical properties between biological tissues and electronic devices,and provides highly-compliant,conformal and stretchable bio-electronic interfaces. Here we also describe the following three applications of the stretchable electrode arrays:a. monitoring intracranial electroencephalography (EEG);b. stimulating peripheral nerves to drive muscles;c. monitoring epicardial electrocardiography (ECG). Stretchable microelectrode arrays create a promising field in biomedical applications for its better modulus match with biological tissues and robust mechanical and electrical properties. They allow for construction of electronic integrated circuits spread over on complex and dynamic curved surfaces,providing a much friendlier bio-electronic interface for diagnosis,treatment and intelligent bio-control. Most biological tissues are supple and elastic, while current electronic devices fabricated by semiconductors and metals are usually stiff and brittle. As a result, implanted electronic devices can irritate and damage surrounding tissues, causing immune reaction and scarring. In this work, we develop stretchable microelectrode arrays, with the development of a novel soft lithography technology, which are designed and fabricated with a polymer / stretchable metal / polymer sandwich structure. With the great deformability of stretch, compression, bend and twisting, while preserving electrical property, this technology overcomes the fundamental mismatch of mechanical properties between biological tissues and electronic devices, and provides highly-compliant, conformal and stretchable bio-electronic interfaces. a we have the following three applications of the stretchable electrode arrays: a. monitoring intracranial electroencephalography (EEG); b. stimulating peripheral nerves to drive muscles; c. monitoring epicardial electrocardiography (ECG). Stretchable microelectrode arrays create a promising field in biomedical applications for its better modulus match with biological tissues and robust mechanical and electrical properties. They allow for construction of electronic integrated circuits spread over complex and dynamic curved surfaces , providing a much friendlier bio-electronic interface for diagnosis, treatment and intelligent bio-control.