An electronic tongue (E-tongue) comprises a series of sensors that simulate human perception of taste and embedded artificial intelligence (AI) for data analysis and recognition. Traditional E-tongues based on electrochemical methods suffer from a bulky size and require larger sample volumes and extra power sources, limiting their applications in in vivo medical diagnosis and analytical chemistry. Inspired by the mechanics of the human tongue, triboelectric components have been incorporated into E-tongue platforms to overcome these limitations. In this study, an integrated multichannel triboelectric bioinspired E-tongue (TBIET) device was developed on a single glass slide chip to improve the device’s taste classification accuracy by utilizing numerous sensory signals. The detection capability of the TBIET was further validated using various test samples, including representative human body, environmental, and beverage samples. The TBIET achieved a remarkably high classification accuracy. For instance, chemical solutions showed 100% identification accuracy, environmental samples reached 98.3% accuracy, and four typical teas demonstrated 97.0% accuracy. Additionally, the classification accuracy of NaCl solutions with five different concentrations reached 96.9%. The innovative TBIET exhibits a remarkable capacity to detect and analyze droplets with ultrahigh sensitivity to their electrical properties. Moreover, it offers a high degree of reliability in accurately detecting and analyzing various liquid samples within a short timeframe. The development of a self-powered portable triboelectric E-tongue prototype is a notable advancement in the field and is one that can greatly enhance the feasibility of rapid on-site detection of liquid samples in various settings.

This work describes a two-chip acoustofluidic platform for two-dimensional (2D) manipulation of microparticles in a closed microchamber on a reusable surface acoustic wave (SAW) device. This platform comprises two microfabricated chips: (1) a detachable silicon superstrate enclosed by a PDMS microfluidic chamber and (2) a reusable SAW device for generating standing SAW (SSAW), which is typically an expensive component. Critical to such a two-chip acoustofluidic platform is the selection of a suitable coupling agent at the interface of the SAW device and superstrate. To this end, we applied a polymer thin film as a coupling agent that balances between acoustic coupling efficiency, stability over time, and reusability. Recycling of the SAW device lowers the cost-barrier for acoustofluidic particle manipulation. The SSAW is transmitted into the silicon superstrate via the coupling agent to form a standing Lamb wave (SLW) to trap and move microparticles. The reported two-chip strategy enables the single-use microfluidic superstrates to avoid chemical and biological contaminations, while maintaining the merits of acoustofluidic manipulation of being noncontact and label-free and applicable to a wide range of microparticles with different shapes, density, polarity, and electrical properties.