Comprehensive characterization of a microfluidic platform for DEP manipulation and bio-impedance detection using multi-sized polystyrene microbeads

Abstract Dielectrophoresis (DEP) manipulation combined with micro-electric impedance spectroscopy (µEIS) presents a sophisticated approach for cellular analysis and dielectric characterization. While conventional cell analysis techniques rely on complex labeling methods with inherent limitations, integrating DEP and µEIS offers non-invasive, label-free cellular characterization with enhanced sensitivity. This study presents an innovative dual-mode DEP platform incorporating both levitation (LEV DEP ) and rotational (ROT DEP ) forces, integrated with high-precision impedance measurement capabilities on one chip, enabling simultaneous Cell controlling and manipulation and dielectric signature extraction within a single microfluidic device. The fabricated and developed microfluidic platform demonstrated exceptional particle discrimination through the dual mode, with distinct responses for both particle populations. Under $$F_{lEV.DEP}^{10.4 \mu m}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>F</mml:mi> <mml:mrow> <mml:mi>l</mml:mi> <mml:mi>E</mml:mi> <mml:mi>V</mml:mi> <mml:mo>.</mml:mo> <mml:mi>D</mml:mi> <mml:mi>E</mml:mi> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10.4</mml:mn> <mml:mi>μ</mml:mi> <mml:mi>m</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> 2.01 MHz showed a 63.4% magnitude increase, while $$F_{lEV.DEP}^{24.9 \mu m }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>F</mml:mi> <mml:mrow> <mml:mi>l</mml:mi> <mml:mi>E</mml:mi> <mml:mi>V</mml:mi> <mml:mo>.</mml:mo> <mml:mi>D</mml:mi> <mml:mi>E</mml:mi> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>24.9</mml:mn> <mml:mi>μ</mml:mi> <mml:mi>m</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> , particles exhibited a higher 81.2% increase at the same force, yielding a 2.48 × enhancement in discrimination ratio compared to no-DEP conditions. ROT DEP at 110 kHz induced even more pronounced differences, with $$F_{ROT.DEP}^{10.4 \mu m}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>F</mml:mi> <mml:mrow> <mml:mi>R</mml:mi> <mml:mi>O</mml:mi> <mml:mi>T</mml:mi> <mml:mo>.</mml:mo> <mml:mi>D</mml:mi> <mml:mi>E</mml:mi> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>10.4</mml:mn> <mml:mi>μ</mml:mi> <mml:mi>m</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> showing a 120% magnitude increase (phase patterns: −24.501° to −34.363°) and $$F_{ROT.DEP}^{24.9 \mu m}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>F</mml:mi> <mml:mrow> <mml:mi>R</mml:mi> <mml:mi>O</mml:mi> <mml:mi>T</mml:mi> <mml:mo>.</mml:mo> <mml:mi>D</mml:mi> <mml:mi>E</mml:mi> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>24.9</mml:mn> <mml:mi>μ</mml:mi> <mml:mi>m</mml:mi> </mml:mrow> </mml:msubsup> </mml:math> µm particles demonstrating a 145% increase (phase patterns: −31.267° to −42.891°), achieving a 3.16 × discrimination ratio enhancement. The impedance spectrum revealed distinct frequency-dependent signatures, with ROT DEP showing superior mid-frequency discrimination (10.4 µm: 1.9370× $${10}^{4}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>4</mml:mn> </mml:msup> </mml:math> Ω vs 24.9 µm: 2.0542× $${10}^{4}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>4</mml:mn> </mml:msup> </mml:math> Ω at 110 kHz) and LEV DEP optimizing high-frequency characterization (10.4 µm: 1.6677× $${10}^{4}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>4</mml:mn> </mml:msup> </mml:math> Ω vs 24.9 µm: 1.5849× $${10}^{4}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>4</mml:mn> </mml:msup> </mml:math> Ω at 2.01 MHz). These signatures demonstrate the platform’s comprehensive particle characterization capabilities through complementary DEP forces. The dual-mode approach enhanced discrimination ratios by 2.48 × under $$Lev. force$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>e</mml:mi> <mml:mi>v</mml:mi> <mml:mo>.</mml:mo> <mml:mi>f</mml:mi> <mml:mi>o</mml:mi> <mml:mi>r</mml:mi> <mml:mi>c</mml:mi> <mml:mi>e</mml:mi> </mml:mrow> </mml:math> and 3.16 × under $$LEV. force$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>E</mml:mi> <mml:mi>V</mml:mi> <mml:mo>.</mml:mo> <mml:mi>f</mml:mi> <mml:mi>o</mml:mi> <mml:mi>r</mml:mi> <mml:mi>c</mml:mi> <mml:mi>e</mml:mi> </mml:mrow> </mml:math> at selected characteristic frequency range compared to $$NonDEP force$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>NonDEPforce</mml:mi> </mml:mrow> </mml:math> conditions. Comprehensive impedance analysis through frequency spectrum (10 kHz—2.01 MHz) revealed unique frequency-dependent cell signatures, $$ROT. force$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/Mat