A device for interfacing with an internal biological tissue, the device comprising: a flexible and stretchable substrate (104, 112) having an inner surface and an external surface (122, 123), wherein the inner surface defines an enclosure to enclose the internal biological tissue; a flexible and stretchable electronic device or device component (101, 111) comprising one or more sensors, actuators or both supported by the inner surface of the flexible or stretchable substrate (104, 112); the sensors, the actuators or both comprising one or more inorganic semiconductor components, one or more metallic components, or one or more inorganic semiconductor components and one or more metallic components; wherein at least a portion of the inorganic semiconductor components, the metallic components or both have a thickness less than or equal to 500 microns; and wherein the flexible and stretchable substrate (104, 120) and the electronic device or device component (101, 111) provide a net bending stiffness of the system low enough such that the inner surface of the substrate (104, 120) is capable of establishing conformal contact with at least 70% of an outer surface (122, 123) of the internal biological tissue, wherein the flexible and stretchable substrate (104, 120) and the electronic device or device component (101, 111) generates a contact force generated by an elastic force of the enclosure in an expanded state (131, 132) wherein the contact force corresponds to a contact pressure that is sufficiently low to avoid an adverse physiological response from the internal biological tissue and remains sufficiently high to maintain said conformal contact; wherein the contact pressure is greater than or equal to 10 Pa and less than or equal to 1 kPa and is substantially uniformly distributed over an outer surface (122, 123) of the internal biological tissue in conformal contact with the flexible and stretchable substrate (104, 120); wherein a peak pressure is less than or equal to 3 times the contact pressure averaged over the outer surface of the internal biological tissue in conformal contact with the flexible and stretchable substrate (104, 120). a flexible and stretchable substrate (104, 112) having an inner surface and an external surface (122, 123), wherein the inner surface defines an enclosure to enclose the internal biological tissue; a flexible and stretchable electronic device or device component (101, 111) comprising one or more sensors, actuators or both supported by the inner surface of the flexible or stretchable substrate (104, 112); the sensors, the actuators or both comprising one or more inorganic semiconductor components, one or more metallic components, or one or more inorganic semiconductor components and one or more metallic components; wherein at least a portion of the inorganic semiconductor components, the metallic components or both have a thickness less than or equal to 500 microns; and wherein the flexible and stretchable substrate (104, 120) and the electronic device or device component (101, 111) provide a net bending stiffness of the system low enough such that the inner surface of the substrate (104, 120) is capable of establishing conformal contact with at least 70% of an outer surface (122, 123) of the internal biological tissue, wherein the flexible and stretchable substrate (104, 120) and the electronic device or device component (101, 111) generates a contact force generated by an elastic force of the enclosure in an expanded state (131, 132) wherein the contact force corresponds to a contact pressure that is sufficiently low to avoid an adverse physiological response from the internal biological tissue and remains sufficiently high to maintain said conformal contact; wherein the contact pressure is greater than or equal to 10 Pa and less than or equal to 1 kPa and is substantially uniformly distributed over an outer surface (122, 123) of the internal biological tissue in conformal contact with the flexible and stretchable substrate (104, 120); wherein a peak pressure is less than or equal to 3 times the contact pressure averaged over the outer surface of the internal biological tissue in conformal contact with the flexible and stretchable substrate (104, 120).