Abstract: A multilayer flexible electronics platform is an apparatus that allows modular thin-film electronics to be integrated into everyday flexible, flat objects such as pieces of clothing, material coatings, or wearable devices. The apparatus includes a flexible water-impermeable envelop, a flexible power-source layer, a flexible printed circuit board (PCB) layer, and a flexible accessory-interfacing layer. The flexible accessory-interfacing layer allows those modular thin-film electronics to be electronically and electrically attached to the apparatus. The flexible PCB layer allows the apparatus to control and manage those modular thin-film electronics. The flexible power-source layer is used to provide electrical power to those modular thin-film electronics. The flexible water-impermeable envelop protectively encloses those modular thin-film electronics and the aforementioned functional layers of the apparatus.