PEDOT:PSS-Based Disposable Humidity Sensor for Skin Moisture Monitoring

Abstract

This paper presents a flexible and disposable humidity sensor based on Poly (3,4ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The sensing layer is developed by drop casting PEDOT:PSS on screen printed graphene-carbon (G-C) ink based interdigitated electrodes (IDEs) on paper substrate. The humidity sensing properties are investigated in a wide humidity range (25 %RH -90 %RH) at room temperature (RT; 27 ºC ± 2 ºC). The sensor exhibits substantial % response (118.5 % at 90 %RH) in the considered range with response/recovery time as 70/30 seconds (sec). The applicability of the sensor has been demonstrated for skin moisture/humidity monitoring under normal and moist conditions. A read-out circuit is designed for demonstrating the real-time monitoring of skin moisture level. The obtained results indicate the suitability of the developed sensor for applications such as skin moisture monitoring, environmental humidity monitoring, non-contact switching, agriculture, and healthcare industries.

Eco-Friendly Textile-Based Wearable Humidity Sensor with Multinode Wireless Connectivity for Healthcare Applications

“…Furthermore, skin moisture monitoring is another application area for the developed sensor. Unbalanced (either too low or elevated) skin humidity levels can lead to several skin conditions such as fungal infections, dry skin, eczema, allergies, etc. ,, Also, skin moisture monitoring can provide insights into the physiological state, wound healing monitoring, and dehydration-related diseases/conditions (particularly for sportspersons). , Therefore, a humidity sensor can be employed to take precautionary measures based on the skin humidity levels. We tested the developed sensors by measuring the skin humidity levels pre (normal skin) and post (moist skin) by applying a commercial moisturizer, and the results are shown in Figure a,b.…”

“…Humidity sensors have drawn significant attention from the scientific community owing to their applicability in multiple application areas including the healthcare sector, agricultural science, environmental control, and various biomedical processes. − Humidity sensors based on different transduction mechanisms, such as resistance, capacitance, field effect transistors (FETs), and optical fiber have been long established. − Among them, resistive humidity sensors are the most attractive thanks to their low fabrication cost, easy device integration and signal acquisition, cost-effectiveness, easy manufacturing, and low power consumption. ,, Further, humidity sensors based on flexible and wearable electronics can play an important role, especially for personal and wearable healthcare applications. , To attain favorable flexibility, miscellaneous ductile materials such as poly­(ethylene terephthalate) (PET), poly­(dimethylsiloxane) (PDMS), paper, and poly­(ethylene naphthalate) (PEN) have been extensively explored and utilized to develop wearable humidity sensors. ,− However, limited breathability and hygroscopicity properties of polymer film-based sensors significantly lower their comfort and sensitivity; whereas, vulnerability and wetness wrinkles are the major shortcomings of paper-based sensors . Recently, textile (cotton) has been explored as an appropriate substitute for the development of wearable electronic sensing devices. − Their remarkable properties like wearability, excellent flexibility, knittability, superior mechanical compliance, and conformability make them extremely suitable for wearable sensing technologies. ,, Further, owing to their structural, hygroscopic, breathable, and biodegradable properties, the textiles seem highly suitable for developing humidity sensors along with promoting a shift toward eco-friendly electronics. , …”

Flexible humidity sensor based on PEDOT:PSS/Mxene nanocomposite

“…For humidity detection, resistivity of sensor increased with increasing RH between 40% and 80% and then started decrease above 80% RH. Beniwal et al [45] prepared humidity sensor for skin moisture based on PEDOT:PSS screened on graphene-carbon-ink-based interdigitated electrodes. The sensor exhibited substantial 118.5% response from 25% to 90% RH.…”

Triboelectric nanogenerator based on electrospun molecular ferroelectric composite nanofibers for energy harvesting

“…Therefore, a huge impetus is driven towards diverse energy-harvesting technologies that utilize different effects (e.g., thermoelectric, piezo-electric, electromagnetic, pyroelectric and triboelectric). [6][7][8][9][10][11][12][13][14] Among several energy-harvesting technologies being explored, triboelectric nanogenerators (TENGs) hold great promise because of their extensive versatility. Ease of fabrication, distinct device design, wide array of material availability and remarkable power-conversion efficiencies render them highly attractive towards the escalating problems that the energy sector is facing.…”