Flexible power for flexible electronics: A challenge for flexible electronics is to couple devices with power sources that are also flexible. Ideally, they could also be processed in a way that is compatible with current microfabrication technologies. Huang et al. deposited a relatively thick layer of TiC on top of an oxide-coated Si film. After chlorination, most, but importantly not all, of the TiC was converted into a porous carbon film that could be turned into an electrochemical capacitor. The carbon films were highly flexible, and the residual TiC acted as a stress buffer with the underlying Si film. The films could be separated from the Si to form free-floating films, with the TiC providing a support layer. Science , this issue p. 691

The fabrication of miniaturized electrochemical energy storage systems is essential for the development of future electronic devices for Internet of Thing applications. This paper aims at reviewing the current micro-supercapacitor technologies and at defining the guidelines to produce high performance micro-devices with special focuses onto the 3D designs as well as the fabrication of solid state miniaturized devices to solve the packaging issue.

The Internet of Things, enabled by a worldwide network of interconnected sensors, is limited in its large-scale deployment of nomadic miniaturized devices due to the bounds of energy self-sufficiency. One possible solution, albeit challenging, is constructing on-chip pseudocapacitive micro-supercapacitors. Herein, we achieve the collective fabrication of micro-supercapacitors based on sputtered bi-functional vanadium nitride films acting as the electrode material and as the current collector. The reported surface and volumetric capacitance values (1.2 F cm⁻² and >700 F cm⁻³, respectively) of the 16 μm-thick vanadium nitride film obtained via production-compatible microelectronic deposition methods compete well with those of cutting-edge transition metal oxide/nitride materials, and exceed those of standard carbon electrodes. An arsenal of advanced techniques has been deployed to investigate the pseudocapacitive behavior of sputtered vanadium nitride films in aqueous electrolyte in order to unveil the charge storage process explaining their high capacitance and their improved cycling behavior.

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