Post-endovascular aneurysm repair (EVAR) surveillance requires frequent imaging to monitor for risk of late rupture. Endoleaks particularly remain a major risk of EVAR, as they elevate aneurysm sac pressure, often without obvious symptoms. However, current imaging-based surveillance is intermittent and lacks continuous monitoring, leaving a temporal blind spot, often forcing patients to miss the gold opportunity for an intervention. In this paper, we report a self-powered piezoelectric Smart Stent for real-time intra-graft sensing, paired with Endoleak classification by multidomain signal analysis and machine learning. The Smart Stent integrates a mechanically compliant 25 wt% barium titanate (BTO)-polydimethylsiloxane (PDMS) onto a 3D-printed nylon scaffold, enabling efficient electromechanical transduction of pulsatile vascular pressure and flow into electrical signals. In the abdominal aortic aneurysm (AAA) phantom model, the Smart Stent generated voltage outputs up to 186.8 mV at 119.9 mmHg and exhibited a strong linear correlation with pressure and flow. Distinct electrical signatures were observed under simulated Endoleak. Type I and III produced significant baseline voltage reductions (65.2% and 77.5%, respectively), whereas Type II leaks resulted in elevated and irregular voltage signals associated with retrograde flow. Multidomain analysis across time, time-frequency, and feature domains revealed characteristic signal patterns that enabled differentiation of hemodynamic states. Machine learning classification using Singular Value Decomposition (SVD) demonstrated high performance under mixed-trial interpolation conditions and moderate generalization under cross-trial extrapolation. The Smart Stent, paired with machine learning, establishes a continuous, implantable, data-driven sensing platform for improved post-EVAR surveillance.
We present a laser-fabricated platform integrating a laminated capillary-driven microfluidic system with a laser-induced graphene (LIG) heater for on-chip loop-mediated isothermal amplification (LAMP) targeting human papillomavirus type 16 (HPV16) DNA. Both the microfluidic channels and LIG heater were patterned using a CO2 laser system, providing a rapid and mask-free fabrication strategy. The laminated microfluidic architecture enables passive capillary-driven fluid transport without external pumps and incorporates a push valve to retain the reaction mixture during amplification and release the amplified products into the downstream detection zone. LAMP reagents and a dicationic pyridine fluorescent dye (PY2+) were preloaded onto glass fiber pads within the channel, reducing manual reagent addition. The LIG heater, positioned directly beneath the amplification chamber, provided localized Joule heating for on-chip LAMP operation. Following LAMP, valve activation released the amplified products into the detection zone, where binding of PY2+ to double-stranded DNA generated a visible fluorescence. The platform was evaluated using HPV16 plasmid DNA concentrations from 0.01 pg/μL to 0.01 μg/μL, with calculated LOD and LOQ values of 0.019 pg/μL and 0.37 pg/μL, respectively. Assay specificity was supported by the absence of cross-reactivity toward the tested nontarget genital tract pathogens. By integrating capillary-driven fluid handling, reagent pre-storage, localized heating, and downstream fluorescence detection, the platform provides a simplified approach to integrated nucleic acid amplification and detection and a foundation for future portable sample-to-result analysis.
Portable nucleic acid amplification platforms commonly use an external thermostat clamped to the reaction cartridge, which introduces interfacial thermal resistance, constrains heater geometry, and reduces the reaction volume maintained within the target temperature range. This work reports a battery-powered lab-on-a-chip biosensing platform that addresses this limitation by directly laminating a flexible silver–polyimide microheater beneath a micro-milled poly(methyl methacrylate) (PMMA) microreactor array and regulating temperature through the resistance of the heater track. The heater functions as the transduction-enabling element because amplification performance depends on maintaining the enzymatic reaction volume within the active temperature window. The eight-chamber PMMA chip was fabricated by benchtop micro-milling, with spindle speed and feed rate optimized using a Taguchi design, reducing mean channel-floor roughness from 0.42 μm to 0.12 μm while maintaining channel width within 2.5% of the design value. The heater was fabricated by cleanroom-free surface-modification ion exchange and doctor-blade deposition of an Ag–poly(vinyl alcohol) composite, producing a temperature coefficient of resistance of 0.0019 °C-1 and resistance change below 1% after 5000 bending cycles. Integrated into a handheld closed-loop device, the cartridge maintained the 35–65 °C isothermal window with a worst-case steady-state error of 0.61 °C. At 40 °C, it reached set point within 3 min, drew less than 0.6 W, and limited spatial variation across eight chambers to ±0.2 °C. Finite-element modelling showed that more than 92% of the 20 μL reaction volume remained within ±1 °C. The chip amplified Trypanosoma evansi DNA with results concordant with micro-PCR and benchtop PCR.
The management of airway disease based on phenotypic characteristics is limited by the absence of diagnostic tools capable of concurrently addressing multiple inflammatory pathways. Traditional assessments provide isolated measurements, which fail to capture intricate interactions among early immune activation, systemic dissemination, neutrophil recruitment, and viral immune response. These are four critical mechanisms that influence disease progression and therapeutic outcomes. In this study, we introduce a non-faradaic electrochemical impedance spectroscopy biosensor designed for a label-free parallel measurement of C-reactive protein (CRP), IP-10 (CXCL10), interleukin-6 (IL-6), and interleukin-8 (IL-8). The platform uses frequency-specific impedance analysis to detect binding events in capacitance at the electrode-electrolyte interface, allowing for direct concentration-dependent detection. It offers wide dynamic ranges covering both physiological and pathological concentrations for all four analytes. Analytical validation showed a strong correlation between spiked and recovered concentrations (R2 > 0.95), with percent recovery within the 80-120% accuracy range and cross-reactivity below 20% under multiplexed conditions, confirming the platform's selectivity and quantitative reliability. Both intra- and inter-assay reproducibility met analytical standards. By incorporating four distinct inflammatory biomarkers into a single impedance framework, this platform moves airway diagnostics beyond isolated measurements to a multi-dimensional phenotype resolution, laying the groundwork for decentralized risk assessment and therapy-guided inflammatory monitoring.
