High-performance electrochemical power generation humidity sensor based on NaCl/sodium alginate humidity sensing electrolyte and Cu/Zn electrodes for visual humidity indication and respiratory patterns detection

• Published in: Sensors and actuators. B, Chemical Chemical, 2024-06, Vol.409, p.135585, Article 135585
• Main Authors: Duan, Zaihua, Zhang, Boyu, Zhang, Mingxiang, Yuan, Zhen, Jiang, Yadong, Tai, Huiling
• Format: Article
• Language: English
• Subjects: Humidity sensor; Power generation; Primary battery; Respiratory patterns detection; Sodium alginate; Visual humidity indication
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2024.135585

Electrochemical power generation humidity sensors have received great attention recently, but it is challenging for achieving good humidity sensing and power generation performances simultaneously. Herein, we construct a high-performance power generation humidity sensor based on NaCl/sodium alginate (SA) humidity sensing electrolyte and Cu/Zn electrodes. Benefiting from the reasonable selection of humidity sensing electrolyte and electrode materials and the design of sensor structure, the optimized NaCl/SA humidity sensor exhibits wide humidity sensing detection range (10.9−91.5% relative humidity (RH)), short response time (5.6 s), and good repeatability (20 cycles) at 25°C. Importantly, the humidity sensor has high response voltage (∼0.7 V), large short circuit current (∼24 μA) and loading power (∼2.63 μW) at 91.5% RH. The NaCl/SA humidity sensor can be used for passive visual humidity indication by connecting it to a pointer microammeter. In addition, we designed signal processing circuit and software program to recognize respiratory patterns using NaCl/SA humidity sensor. This work not only achieves a high-performance electrochemical humidity sensor, but also provides a useful reference for its applications in passive visual humidity and respiratory patterns detections. [Display omitted] •The electrochemical humidity sensor is fabricated using NaCl/sodium alginate (SA).•The NaCl/SA sensor can output voltage at a wide humidity range of 10.9−91.5% RH.•The NaCl/SA sensor exhibits short response time (5.6 s) at 91.5% RH.•The NaCl/SA sensor can achieve visual humidity indication and respiration detection.