Disclosed are methods for fabrication of flexible circuits and electronic devices in cost effective manner that can include integration of submicron structures directly onto target substrates compatible with industrial microfabrication techniques. In one aspect, a method to fabricate an electronic device, includes depositing an electrically conductive layer on a processing substrate including a weakly-adhesive interface layer on a support substrate; depositing an insulating layer on the conductive layer to attach to the conductive layer; forming a circuit on the processing substrate by etching selected portions of the conductive layer based on a circuit design; and producing a flexible electronic device by attaching a flexible substrate to the formed circuit on the processing substrate and detaching the circuit and the flexible substrate from the interface layer, in which the flexible electronic device includes the circuit attached to the flexible substrate.