The seamless and adaptive interactions between functional devices and their environment are critical for advancing emerging technologies, e.g. wearable devices, consumer electronics, and healthcare. The state-of-the-art electronics are based on planar and rigid structures, limiting their integration with three-dimensional soft biological systems. Mechanically deformable devices incorporating confined liquids present an ideal platform for enabling the conformal coverage of electronics on curved and soft surfaces in related applications. However, to date, liquid-based devices have been limited to merely incorporate liquid components as the passive electrodes given the difficulty in the fabrication of liquid-based heterojunctions. The heterogeneous interfaces between functional materials are the central constituents in the state-of-the-art electronics and optoelectronics. Moreover, there is a lack of the fundamental understanding and technological capability of monolithically integrating liquid structures (e.g. electrodes) with functional materials, in particular, the inorganic semiconductors that offer desired electronic and optoelectronic properties in the anticipated applications.

Here, we demonstrate for the first time a versatile platform for the monolithic integration of liquid-solid heterojunction devices through the hybrid manufacturing of self-assembled two-dimensional inorganic semiconductor nanostructures on additively-manufactured liquid electrodes. This new class of wearable devices are conformable to human skins and can sustainably perform non-invasive physiological functions, e.g. detection of pulses and vocal vibration, by harvesting the operation power from the human body. This research is expected to have a positive impact and immediate relevance to many societally pervasive areas, e.g. biomedical monitoring, consumer electronics, and human-machine interface.