A non-printed integrated-circuit textile for wireless theranostics

Flexible electronics promise AI-assisted healthcare through continuous monitoring of personal physiological data. Sweat composition provides quantitative indices for early diagnosis of diseases, but current integrated electronic (IC) systems are predominantly built on rigid or semi-rigid printed circuit boards (PCBs) attached as patches or boxes, which compromises comfort, breathability, and long-term wearability. Although progress has been made toward integrating electronics into textiles and the broader vision of a fabric computer, most systems still rely on PCB modules for circuit integration. The key challenge is to realize a woven-textile alternative to PCBs that uses fiber-shaped elements and achieves full circuit integration through the weaving process itself. The authors present a non-printed integrated-circuit textile (NIT) assembled entirely by weaving fiber devices (transistors, sensors, diodes, solar cells, batteries) and interlaced nodes into cloth-like IC modules for sensing, amplification, logic computation, wireless transmission, and sustainable power, enabling a soft, breathable, cable-free system for continuous on-body AI monitoring and emergency assistance.

Device and circuit fabrication employed a weaving-centric process analogous to Jacquard weaving, integrating fiber devices and interlaced device nodes directly into textiles. The process comprised: (1) fabrication of integrated function strings (warps or wefts) containing multiple device sections on a single fiber substrate in a section-by-section layout; (2) weaving these strings to form device nodes (e.g., transistor junctions) and circuit interconnections.

Textile transistors: Fabric-type electrochemical transistors were formed at warp–weft junctions of two PEDOT:PSS-coated cotton fibers, separated by a cotton spacer and contacted by an aqueous gel electrolyte (8 wt% sorbitol, 33 wt% PSS, 0.1 M NaClO4, 12 wt% glycol, H2O), then encapsulated in PMMA. PEDOT:PSS-1000 doped with 10 wt% diethylene glycol (DEG) and 0.5 wt% PEG-2000 was brush-coated on cotton wires; terminals were made by coaxial MWCNT coatings. Devices operate via ion-driven electrochemical gating (Na-ion doping/de-doping in PEDOT:PSS), providing depletion-mode characteristics and mechanical robustness under bending/stretching.

Sensor modules:

• Wire-type pH (sweat) sensor: PANI grown in situ on polymer wire by immersing in aniline/HCl solution, followed by oxidative polymerization with (NH4)2S2O8/HCl under ice bath; coaxial MWCNT terminals added. Sensing relies on reversible protonation/deprotonation of PANI (emeraldine salt/base), yielding resistance changes proportional to pH (3–8).
• Wire-type motion (piezoresistive) sensor: AC/PVDF slurry (AC:PVDF 3:1 in NMP) coated on an elastic wire; MWCNT terminals added. Stretching increases interparticle distances in AC/PVDF, increasing resistance; characterized over 0–40% tensile strain.
• Wire-type light sensor: A fiber electrode (PBT/Cu/Mn/ZnO nanowires sensitized with N719 dye/CuI) was fabricated via chemical Cu plating on polymer wire, Mn electroplating, hydrothermal ZnO nanowire growth (Zn(CH3CO2)2 and HMTA), dye sensitization, and CuI deposition; an Au wire was helically wound as counter/collector, sealed in PMMA. Photogeneration at ZnO/dye/CuI interface produces bias/current proportional to illumination.

Power modules:

• Textile photovoltaic cells: Fiber-based photoanodes similar to light sensor but with longer ZnO nanowires (Zn(CH3CO2)2 0.03 M, HMTA 0.03 M) were woven with Au-coated Cu counter electrodes via shuttle weaving. Modules connected in series or parallel to scale Voc and Isc, respectively.
• Zn/MnO2 battery fibers: MnO2 slurry (CB:MnO2:PVDF = 2:7:1 in NMP) prepared hydrothermally; MnO2 coated on PET/MWCNT wire and paired with PET/MWCNT/Zn wire in gel electrolyte (2 M ZnSO4, 0.4 M MnSO4, PVA 100 g/L), then encapsulated in PMMA.
• Polymer dielectric capacitors: PVDF/NMP solution (2.5 g/L) coated on Cu-coated cotton section; thin Cu wire wound around to form a wire-shaped capacitor (~100 pF) for power filtering.
• Blocking diodes integrated to prevent PV–battery self-discharge.

Wireless communication: Wire-type infrared LED cable fabricated by mounting AlGaAs IR chips (SLLT6393A) in parallel between two Au wires on a polymer strip; terminals connected with conductive paste and encapsulated. Employed for optical data transmission and logic-coded alerts.

Circuit weaving and integration: Integrated function strings (e.g., optical sensor + PEDOT:PSS gate; resistor + battery) were used as wefts interwoven with MWCNT-coated or PEDOT:PSS warps to form: (i) transistor nodes via electrolyte-bridged junctions; (ii) interconnections between resistor-battery strings and sensor-transistor strings, yielding textile amplifier modules (common-collector) and logic gates (AND, OR, AND-OR). Encapsulation with PMMA improved comfort and durability.

Characterization: Electrochemical performance and EIS measured with CHI600E workstation; SEM (JEOL JSM-7800F) for morphology; resistances derived from I–V slopes; photovoltaic tests under AM 1.5 (1000 W/m², San-Ei XES40). Wireless transmission assessed under various bending angles and after 5000 bending cycles. Waterproofing and thermal stability evaluated under varying humidity and temperature.

Weaving workflow: Warps pre-aligned and alternately tilted to create sheds; integrated device wefts inserted to form contact nodes and connections per circuit design. Repeated cycles yielded a complete NIT containing sensing, logic, wireless, and power modules.

• Woven electrochemical transistors: Depletion-mode PEDOT:PSS/gel devices achieved on/off conductivity drop >3000× with gate voltage increase from 0 to 1.5 V; pinch-off voltage ~1.1 V. Assembled on paper, PVC, and cotton substrates with on/off ratios >10^3. Adding ≥1 wt% diethylene glycol (DEG) to PEDOT:PSS improved on/off ratio by >3 orders of magnitude; electrochemical analysis showed additional reversible redox peaks around ±1 V, suggesting enhanced deep Na-ion doping via PEDOT nanocrystal reorganization. Transistor performance remained robust under large deformation (electrode displacement up to 3 cm); gel electrolyte ionic impedance change <2 kΩ versus >20 kΩ total gate–source impedance, enabling deformation-insensitive operation.
• Logic circuits: Textile logic gates (AND, OR, AND-OR) built from woven transistors exhibited correct logic functions with distinct low/high output levels; operation sustained over centimeter-scale channel distances (tested up to ~30 mm).
• Sensors: • Sweat (pH) sensor showed linear, reversible resistance–pH response (pH 3–8) with sensitivity ~40 kΩ per pH unit. • Motion (piezoresistive) sensor displayed linear ΔR/R vs strain with ΔR/R ≈ 2 at 40% tensile strain. • Light sensor provided linear short-circuit current vs light intensity (0–2000 W/m²) with sensitivity ~0.03 A/W; Voc approached a plateau above ~800 W/m².
• Power modules: • Photovoltaics scaled as expected: series increased Voc linearly; parallel increased Isc linearly with the number of fiber photoanodes. • Zn/MnO2 battery fibers achieved capacity up to ~190 mAh g⁻1; series/parallel configuration scaled voltage/capacity. • Integrated photo-rechargeable module delivered ~1.8 V under sunlight and supported continuous 0.1 mA discharge for ~18 min. Capacitive filtering (100 pF) reduced supply noise; diodes prevented PV–battery self-discharge.
• Power consumption: Motion and sweat sensing modules required ≤45 μW; light sensor actively harvested energy and could drive transistor without external power. Infrared LED emission for wireless signaling peaked at ~6–8 mW transiently during alerts, then returned to standby.
• Wireless communication: IR optical data transmission operated without external PCB, remained functional at bending angles up to 180°, and retained performance after 5000 bending cycles; low angular dependence of the wire-type IR LED supported flexibility. Waterproof and thermostable operation demonstrated.
• System integration: A fully woven, cable-free NIT prototype continuously monitored motion, sweat, and ambient light; amplified/processed signals; performed logic judgments (e.g., day/night context) and transmitted alerts wirelessly. Logic-coded alert levels (0, 1, 2) enabled differentiated responses for scenarios such as diurnal dehydration (level 1), nocturnal fever or epilepsy/falls (level 2).

The study addresses the central challenge of replacing rigid PCB-based integration with a textile-native approach by demonstrating a fully woven non-printed integrated-circuit textile that integrates sensing, signal conditioning, logic operations, wireless communication, and sustainable power. Electrochemical fiber transistors, leveraging ion-driven gating in PEDOT:PSS, provide high on/off ratios, low-voltage operation, and exceptional mechanical tolerance to bending and stretching. This robustness and the ability to assemble devices on common textile substrates enable scalable, low-cost manufacturing compatible with standard weaving methods. The sensor suite captures key physiological and environmental parameters (sweat pH, motion, illumination), while amplifier and logic modules condition signals and execute context-aware decisions (e.g., day vs night) to generate binary-encoded alerts. A photo-rechargeable energy module, combining textile photovoltaics, Zn/MnO2 fiber batteries, capacitive filtering, and blocking diodes, supplies stable, continuous power and supports intermittent higher-power wireless transmissions. Together, these modules realize continuous on-body monitoring and autonomous emergency alerting in a breathable, deformable, and washable textile form factor, highlighting a practical pathway toward fabric-like computers and on-body AI hardware for healthcare.

The work demonstrates a woven, non-printed integrated-circuit textile that functions as a self-powered, cable-free platform for multiplexed sensing, logic computation, and wireless communication. By constructing all components as fiber devices or interlaced nodes during weaving, the NIT achieves comfort, breathability, and mechanical resilience while delivering reliable electronics performance. Key contributions include robust ion-gated textile transistors, integrated fiber sensors for sweat, motion, and light, a photo-rechargeable power textile, and logic-coded wireless alerts for simulated medical emergencies. This approach offers a compelling alternative to PCB-based wearables and suggests a route toward fabric-like computing for continuous healthcare monitoring. Future research may expand device density and complexity, integrate additional biomarkers and communication protocols, enhance long-term durability (laundering cycles), and explore large-scale manufacturing and clinical validation.