The pursuit of simple, cost-effective, and efficient flexible ammonia sensors is an area of keen interest. This study aimed to create a highly sensitive, affordable flexible sensing patch (FDP) for immediate ammonia and impedance monitoring. Using a laser direct writing technique, symmetrical graphene patterns were crafted onto commercial kapton tape. These patterns were folded in half, allowing the lower layer to serve as an impedance sensor and the upper layer as an electrode for ammonia detection. The modified Ti 3 C 2 T x MXene solution was introduced as the sensitive layer in response to ammonia gas, and we also explored how varying thicknesses of this sensitive layer affected the response results. Notably, the results highlighted that FDPs with two thicknesses (50 μL solution) offered optimal ammonia detection. With a detection limit of 150 ppb, impressive sensitivity (18.08%/ppm), exceptional linearity (0.996), and stability within the 0.5 ppm–20 ppm range, the overall performance of the FDP surpassed that of most reported ammonia sensor devices based on graphene materials. FDP was able to better characterize the shelf life of lamb at a cost of no more than $1.5. This study provides solutions for rapid ammonia detection and food quality assessment .
Developing a simple and rapidly preparative method for patterned flexible supercapacitors is essential and indispensable for the swift advancement of portable devices integrated with micro devices. In this study, we employed a cost-effective and rapid fabrication method based on transfer-printing technology to produce patterned micro flexible supercapacitors with various substrates. The resulting flexible micro supercapacitors not only allow for customized patterns with strong flexibility and resistance to bending, while maintaining a certain level of performance, but also facilitate the creation of diverse circuits to tailor voltage and current to specific requirements. Patterned micro flexible supercapacitors with a thickness of 0.02 mm, based on accordion-like Ti3C2Tx MXene materials coated on a substrate, demonstrate a specific capacitance of 142.7 mF cm–2 at 0.5 mA cm–2. The devices exhibit satisfactory capacitance retention (91% after 5000 cycles) and superb mechanical flexibility (71% capacitance retention at 180° bending after 2000 cycles). At a power density of 2.9 mW cm–2, the energy density of the sandwich structure device reaches 126.8 μWh cm–2. This study is expected to contribute new ideas for the design and preparation of patterned flexible supercapacitors.
危险品化学品经营许可证（带存储）