WS2 Microengineering Taking laboratory diagnosis into the field 1/19
The team Professor Wamadeva Balachandran (Bala) Principal Investigator Dr Krishna Burugapalli Professor Rob Evans Professor Chris Hudson Dr Predraig Slijpevic Dr Jeremy Ahern Dr Nada Manivannan Dr Yanmeng Xu Dr Ruth Mackay Biomedical Biosciences Electronic Engineering Biosciences Microfabrication Multiphysics Modelling Printed Electronics BioMEMS/NEMS Engineering Sivanesan Tulasidas Tosan Ereku Pascal Craw Sara Chaychian Branavan Nehru Sana Hussain Shavini Wijesuriya PhD Student PhD Student PhD Student PhD Student PhD Student Visiting Scholar PhD Student Wireless Biomedical Engineering Engineering Design Electrical Engineering Paper microfluidics Biosciences Engineering Design 2/19 Communication
WS2 Microengineering Balachandran Lab, Brunel University • Lab-on-chip for POCT concept • Patient sample collection • Microfluidics • DNA extraction • Isothermal amplification • Nucleic acid detection • Electronic control and communication • Instrumentation design • Paper-based microfluidics • Future research 3/19
Integrated Lab-On-a-Chip for POCT Integrated Lab-On-a-Chip for POCT Sample collection MicroFluidic Network Sample DNA Extraction DNA DNA concentration & Purification Detection Amplification & cell lysis Wireless Electronic Control System Interface 4/19
Modular Research Platform Sample pre-treatment Electronic System Concentration / Purification Electromagnets Display and User Standardisation Interface Pumps Valve actuators Disposable Cartridge Control System Thermal control Sample & Reagents Microcontroller Interface Interface Nucleic Acid Detector Power Management Microfluidic Lysis Magnetic Network SPR Sensors MEMS Communication Electromagnets Amplification Electrochemical RFID GPS Valves Optical 3G Mobile Bluetooth Pathways Nanowire WiFi USB Detection Waste 5/19
Sample Collection • Swab and urine • 4mL of urine • 100uL swab elute • Simple design ‘Fool-proof’ • Direct integration to extraction device • Integrated lysis Urine collection devices 6/19
Finite element analysis to inform design Cessational flow of urine from six inlets into the air-filled cavity Streamline depiction of flow from inlets to device discharge orifice 7/19
Deformable silicone reservoirs 25uL microfluidic chip Cam actuated pump filling microfluidic chip 8/19
DNA extraction Novel membrane in development • Cationic bioploymer membrane • Reduces number of steps for DNA extraction No chaotropic reagents • Simple pH (5-9) change in aqueous • solutions 2 reagents required • Simple flow over device: no • centrifugation/active mixing Two DNA extraction devices with embedded biopolymer membrane 9/19
DNA Extraction performance 100 90 80 Percentage Recovery (%) 70 60 50 Spin Column (Qiagen) 40 Bioplymer membrane 30 20 10 0 0 0.1 100 Sample Concentration (ng/uL) 10/19
Isothermal Amplification On-chip helicase dependent Helicase dependent amplification • amplification Single temperature (65⁰C) • 10 9 amplification power 10 • < 20minutes reaction time • 9 Can be used with real-time • fluorescence chemistries 8 7 Final DNA concentration (ug/mL) Real-time plot of HDA reaction 6 Positive 5 Control Fluorescence 4 3 2 Negative control 1 0 0 5 10 15 20 25 30 35 40 25µL tube reaction 25µL On-chip reaction Time (minutes) 11/19
On-chip amplification and detection 0 PMMA Reaction Fluidic Chamber Chip 490nm LED Optical Fibre 3mm PMMA Emission band-pass Filter (530nm) 25µL microfluidic chip Amplified Photodiode Finite element analysis of microfluidic chip to characterise thermal properties Fluorescence detection on microfluidic chip 12/19
Magnetic bead-based DNA Detection Planar Spiral Inductor for Inductance-based biosensor 13/19
Magnetic bead-based DNA Detection Simple circuitry to allow detection of magnetic beads Planar Inductor Simulation, Magnetic Flux Density = 4 - 16 mT 14/19
Integrated microfluidic cartridges 10mm 10mm Al mould for a fully integrated microfluidic Brass/Al mould for a detection microfluidic system device 10mm Detection device with Integrated microfluidic PDMS automated fluid flow and device electrodes 15/19
Communication Design Strategy Communication Design Strategy Communication Design Strategy Communication Design Strategy 16/19
Paper based microfluidics (µPADs) Paper based microfluidics (µPADs) Paper based microfluidics (µPADs) Paper based microfluidics (µPADs) Fabrication of µPADs Fabrication of µPADs Fabrication of µPADs Fabrication of µPADs Printed barriers (Wax) Printed barriers of 500 µm Wax penetration: comparison of printed barriers before and after produced fully functional barriers. Cured barriers (Wax) curing at 120 o C for 15 minutes A minimum channel width of ~ 300 µm is achievable. Xerox ColorQube TM Multiplexing: A single DNA mobility on a Inkjet printed silver 8570N solid ink sample effectively µPAD electrodes (25 µm) Printer delivered into 5 test zones 17/19
DNA detection on µPADs DNA detection on µPADs DNA detection on µPADs DNA detection on µPADs 0s – Blank 0 s 90 s W 1 W 2 30 s 30s – 20uL FITC tagged 25mer DNA sample advancing (0.01nM). 90s – Further movement of the sample into the waste zone. W1 – DNA sample getting washed away by water into the waste zone. W2 – Further washing of the DNA by water into the waste zone. Blank paper Serially diluted Water as Serially diluted Serially diluted Stock DNA as control 1pM DNA 0.1pM DNA control solution 0.1nM 0.01nM DNA All above pictures are obtained through the BIO-RAD Gel DOC TM XR+ system and the associated image analysis software Image Lab TM . 18/19
Handheld device development Current handheld platform in development Future GUI 19/19
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