Integration of a Textile Electrode Into a Smart Glove for On-Field Analysis of Fruit Quality

In the field of smart agriculture, the on-site assessment of fruit quality is gaining an increased attention, due to the possibility it offers to precisely and rapidly evaluate fruit quality, enabling real-time decision-making while reducing waste and ensuring a high-quality final produce. In this context, the extreme portability and flexibility of human hand-based tools, such as smart gloves, hold the potential to revolutionize the field. In this study, a textile-based wearable smart glove prototype is presented, combining textile thermoplastic polyurethane-carbon nanofiber (TPU-CNF)-based printed electrodes and a portable impedance analyzer, for on-site fruit monitoring applications. The presented conductive ink, prepared using TPU with a 50-wt% concentration of CNFs, is spray coated onto a stretchable Lycra fabric to prepare the electrodes. The realized electrodes presented good electromechanical behavior when subjected to strain stress of up to 250% (static) and 100% (dynamic, 1000 cycles) and displayed thermal-healing properties upon extreme damage, recovering up to 90% of the starting electrical properties. Furthermore, the employment for bioimpedance analysis on fruit provided reliable results in line with commercial electrodes up to frequencies of 500 kHz, well above the limit of employment of bioimpedance for fruit analysis with portable systems. The final integration within the proposed smart glove prototype, validated with a practical on-plant fruit bioimpedance analysis, proved the quality of the system and paves the way for its extensive on-field application.