Low Hysteresis and Fatigue-Resistant Polyvinyl Alcohol/Activated Charcoal Hydrogel Strain Sensor for Long-Term Stable Plant Growth Monitoring

Abstract

Flexible strain sensor as a measurement tool plays a significant role in agricultural development by long-term stable monitoring of the dynamic progress of plant growth. However, existing strain sensors still suffer from severe drawbacks, such as large hysteresis, insufficient fatigue resistance, and inferior stability, limiting their broad applications in the long-term monitoring of plant growth. Herein, we fabricate a novel conductive hydrogel strain sensor which is achieved through uniformly dispersing the conductive activated charcoal (AC) in high-viscosity polyvinyl alcohol (PVA) solution forming a continuous conductive network and simple preparation by freezing-thawing. The as-prepared strain sensor demonstrates low hysteresis (<1.5%), fatigue resistance (fatigue threshold of 40.87 J m−2), and long-term sensing stability upon mechanical cycling. We further exhibit the integration and application of PVA-AC strain sensor to monitor the growth of plants for 14 days. This work may offer an effective strategy for monitoring plant growth with conductive hydrogel strain sensor, facilitating the advancement of agriculture.

High Linearity, Low Hysteresis Ti3C2Tx MXene/AgNW/Liquid Metal Self‐Healing Strain Sensor Modulated by Dynamic Disulfide and Hydrogen Bonds

“…f) Literature comparison on stretchability and hysteresis of strain sensors in recent years. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] SEM images of the MAL strain sensor (Figure 3g,h) show that the AgNWs lapped the Ti 3 C 2 T x MXene sheets between the layers and the LM acted as a bridge to increase the connection between the Ti 3 C 2 T x MXene and AgNWs. The cross-section SEM image of the self-healing strain sensor with buckled structure can be seen in Figure 3i.…”

A Sprayable Electrically Conductive Edible Coating for Piezoresistive Strain Sensing

“…On the other hand, activated carbon (AC, E 153) is an emerging candidate as edible electronic conductor, because it is authorized as a food additive by the European Food Safety Authority (EFSA), [38] can be eaten in larger quantities (mg kg −1 of body weight per day), [9] is economically affordable (< 0.3 € g -1 ), and is distributed as a powder, [24] which makes it ideal for composite formulations with resistivity in the range 0.5−1000 Ω cm. [24,39−44] AC has been used in combination with polydimethylsiloxane (PDMS), [39,40] concrete, [42] foams, [43] and hydrogels [45] to produce strain sensors for wearable and structural health monitoring applications. Also, a large variety of edible electronics components leveraging AC have been already implemented (e.g., electrochemical sensors, [46] supercapacitors, [47] batteries, [34,35] tilt sensors, [18] triboelectric generators, [41] electrodes, [24] pressure sensors [13] ).…”