Field-effect gating with solid dielectrics is the basis for modern electronics. Electrolyte gating, however, offers far higher polarizations. Indeed, electrolyte gating has been a breakthrough to electrically induce numerous phase transitions in solids. These experiments are all done by dripping mm-size drops of the electrolytes onto the active sample. Compared to integrated circuit technology this approach seems outdated to us. These drops are open to the environment, and allow only for limited purity, reproducibility, and integration.
As reported in Advanced Materials, 1802598 (2018), we have achieved breakthrough to solve these problems. Heterostructure electronic circuits have, up to now, been comprised of solid materials only. We have opened this materials space to also include liquids. We demonstrate integrated liquid capacitors and integrated liquid field effect devices which are of equal quality or even outperform standard, bulk devices. This result will accelerate discoveries based on electrolyte gating by providing a new platform, and opens a new area to exploit liquid/solid interfaces in integrated functional devices with technological promise.