A laser‐Engraved Wearable Electrochemical Sensing Patch for Heat Stress Precise Individual Management of Horse

Abstract In point‐of‐care diagnostics, the continuous monitoring of sweat constituents provides a window into individual's physiological state. For species like horses, with abundant sweat glands, sweat composition can serve as an early health indicator. Considering the salience of such metrics in the domain of high‐value animal breeding, a sophisticated wearable sensor patch tailored is introduced for the dynamic assessment of equine sweat, offering insights into pH, potassium ion (K+), and temperature profiles during episodes of heat stress and under normal physiological conditions. The device integrates a laser‐engraved graphene (LEG) sensing electrode array, a non‐invasive iontophoretic module for stimulated sweat secretion, an adaptable signal processing unit, and an embedded wireless communication framework. Profiting from an admirable Truth Table capable of logical evaluation, the integrated system enabled the early and timely assessment for heat stress, with high accuracy, stability, and reproducibility. The sensor patch has been calibrated to align with the unique dermal and physiological contours of equine anatomy, thereby augmenting its applicability in practical settings. This real‐time analysis tool for equine perspiration stands to revolutionize personalized health management approaches for high‐value animals, marking a significant stride in the integration of smart technologies within the agricultural sector.

where the V and V0 are represent the potential before and after bending, respectively.
The sensor presented satisfactory durability after 400 bending cycles.

Figure S13
. Flexible sensor patches with sweat induce module is covered on the surface of the horse.As a high-value animal, the hair of horse is thick and cannot be completely shaved, which likely leads to water loss in the horse [1,2] .Different from humans, the efficiency of sweat-stimulation in-body sweat analysis of horse is not ideal, so the matching degree between sweat-stimulation system and animal skin needs promotedTable S1.The comparison of recently reported sweat sensors for pH, K + , and temperature determination, where the S represents sensitivity of sensor.

Figure S1 .
Figure S1.Dimensional diagram of the LEG-based wearable patch.

Figure S3 .
Figure S3.SEM and mapping images of PANI/Au/LEG.Elements of Cl, Au, C, and O are evenly dispersed on the surface of PANI/Au/LEG.

Figure S4 .
Figure S4.SEM and mapping images of Ag/LEG.Elements of S, C, O, Na, and Ag are evenly dispersed on the surface of Ag/LEG.

Figure S5 .
Figure S5.EDS spectra of bare LEG, Ag/LEG, and PVB/Ag/LEG.Ag element is appeared on the Ag/LEG and the Cl element is appeared on the PVB/Ag/LEG.

Figure S6 .
Figure S6.Raman spectra of bare LEG and Ag/LEG.The value of ID/IG is obviously changed after Ag modification.

Figure S7 .
Figure S7.Raman spectra of pure PI substrate.There are no characteristic peaks on pure PI substrate.

Figure S11 .
Figure S11.Reproducibility of (A) pH and (B) K + sensors.Five sweat sensors presented similar potential responses.

Figure S12 .
Figure S12.Potential variation of the pH and K + sensors before and after bending,