TITLE:
Microfluidics-Enabled Wearable Biosensing: Materials, Systems, and On-Body Validation
AUTHORS:
Zijun Zhang
KEYWORDS:
Wearable Biosensing, Microfluidics, Sweat, Tear, Interstitial Fluid, Biofuel Cell, On-Body Validation
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.13 No.12,
December
17,
2025
ABSTRACT: Microfluidic wearables move microliter biofluids across soft, low-impedance interfaces and into stable transducers on skin, enabling time-stamped chemistry without pumps. In this review (2015-2025), we take a system view: how specific fluidic choices (e.g., capillary-burst gating, chronological reservoirs, bubble control) preserve temporal fidelity; how materials and transduction (PEDOT: PSS hydrogels vs. MXene films; electrochemical vs. colorimetry) set bias and signal-to-noise; and how radios/power must follow use-case cadence. Two case studies ground the discussion: a battery-free NFC (near-field communication) sweat patch that couples passive microfluidics with imaging readout (field-tested colorimetric panels) via field-tested colorimetric panels and a large-cohort chloride/sweat-rate program (n ≈ 312 athletes) linking local measurements to whole-body estimates. We argue that agreement-centric validation (Bland-Altman limits, mean absolute relative difference (MARD), concordance) should be stratified by flow, site, and temperature, and we use energy per insight as a pragmatic yardstick to compare architectures by the energy needed for a minute of trusted trend or a defensible threshold call. We close with falsifiable targets for low-flow operation and sequence-sampled hormones and list open practices to make on-body chemistry more reproducible.