The development of biomimetic skin phantoms is critical for reliable biopotential measurements in wearable sensor applications. A major limitation is hydration instability, as moisture loss alters ionic conductivity and leads to unpredictable impedance behavior. Building on prior work using polyvinyl alcohol (PVA) cryogels as benchtop analogs for electrode evaluation, this study investigates hydrophilic additive integration and freeze-thaw processing as complementary strategies to improve hydration retention and electrical stability. Seven commercial hydrophilic additives were screened for their ability to reduce mass loss and stabilize impedance over time. Aloe Vera proved most effective, reducing mass loss and impedance variability and extending phantom electrical lifespan from approximately 4 days for untreated controls to up to 18 days under optimized conditions. Embedded additive testing identified an optimal concentration of approximately 0.75 g (5.5--6.5% w/w), while higher concentrations produced oversaturation and electrical drift. Freeze-thaw optimization demonstrated that a single cycle preserved structural integrity and minimized dehydration, whereas repeated cycling (≥ 2 cycles) increased mass loss, permittivity decay, and electrical instability. Differential scanning calorimetry quantified the distribution of freezable and bound water within the cryogel matrix. Samples containing the additive exhibited markedly reduced endothermic peak magnitudes during melting, indicating a lower fraction of freezable water and a corresponding increase in tightly bound water. These results establish a combined chemical-physical framework that extends phantom functional lifespan by more than fourfold and provides long-term hydration stability and consistent impedance behavior suitable for repeatable wearable biosensor testing.
Abstract
Journal Article
eng
42050054
Lin, Robert, et al. "Hydration-stable PVA-based Skin Phantom for Wearable Biopotential Sensor Evaluation." Scientific Reports, 2026.
Lin R, Gonzaga M, Lewis CL, et al. Hydration-stable PVA-based skin phantom for wearable biopotential sensor evaluation. Sci Rep. 2026.
Lin, R., Gonzaga, M., Lewis, C. L., & Goyal, K. (2026). Hydration-stable PVA-based skin phantom for wearable biopotential sensor evaluation. Scientific Reports. https://doi.org/10.1038/s41598-026-49790-8
Lin R, et al. Hydration-stable PVA-based Skin Phantom for Wearable Biopotential Sensor Evaluation. Sci Rep. 2026 Apr 28; PubMed PMID: 42050054.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR
T1 - Hydration-stable PVA-based skin phantom for wearable biopotential sensor evaluation.
AU - Lin,Robert,
AU - Gonzaga,Max,
AU - Lewis,Christopher L,
AU - Goyal,Krittika,
Y1 - 2026/04/28/
PY - 2026/02/12/received
PY - 2026/04/16/accepted
PY - 2026/4/29/medline
PY - 2026/4/29/pubmed
PY - 2026/4/28/entrez
KW - Freeze-thaw cycles
KW - Hydration stability
KW - Hydrophilic additives
KW - Impedance
KW - Skin phantom
KW - Wearable sensors
JF - Scientific reports
JO - Sci Rep
N2 - The development of biomimetic skin phantoms is critical for reliable biopotential measurements in wearable sensor applications. A major limitation is hydration instability, as moisture loss alters ionic conductivity and leads to unpredictable impedance behavior. Building on prior work using polyvinyl alcohol (PVA) cryogels as benchtop analogs for electrode evaluation, this study investigates hydrophilic additive integration and freeze-thaw processing as complementary strategies to improve hydration retention and electrical stability. Seven commercial hydrophilic additives were screened for their ability to reduce mass loss and stabilize impedance over time. Aloe Vera proved most effective, reducing mass loss and impedance variability and extending phantom electrical lifespan from approximately 4 days for untreated controls to up to 18 days under optimized conditions. Embedded additive testing identified an optimal concentration of approximately 0.75 g (5.5--6.5% w/w), while higher concentrations produced oversaturation and electrical drift. Freeze-thaw optimization demonstrated that a single cycle preserved structural integrity and minimized dehydration, whereas repeated cycling (≥ 2 cycles) increased mass loss, permittivity decay, and electrical instability. Differential scanning calorimetry quantified the distribution of freezable and bound water within the cryogel matrix. Samples containing the additive exhibited markedly reduced endothermic peak magnitudes during melting, indicating a lower fraction of freezable water and a corresponding increase in tightly bound water. These results establish a combined chemical-physical framework that extends phantom functional lifespan by more than fourfold and provides long-term hydration stability and consistent impedance behavior suitable for repeatable wearable biosensor testing.
SN - 2045-2322
UR - https://www.unboundmedicine.com/prime/citation/42050054/Hydration-stable_PVA-based_skin_phantom_for_wearable_biopotential_sensor_evaluation.
DB - PRIME
DP - Unbound Medicine
ER -
