Safety and effectiveness evaluation of flexible electronic materials for next generation wearable and implantable medical devices

•Flexible electronic technology provides opportunities for next generation wearable and implantable medical devices.•Safety and effectiveness of flexible electronic technology must be proved in intended clinical use.•Flexible electronic materials should balance their properties and biocompatibility.•Biocompatibility assays should be carried out according to contact tissue and duration time.•Conductivity, mechanical compliance and robustness, long-term stability and chemical resistance are key properties.