Research Summary Bioscience and BioengineeringOverviewBiomolecular MicrosystemsMotivationBiomolecular MicromanufacturingSlide 6Biopolymer DepositionElectrodeposition of Chitosan BiopolymerSolution Properties and ElectrodepositionChitosan: Hydrogels & Compact FilmsBiomaterials CharacterizationThermal Desorption Mass SpectroscopySurface & Thin Film Characterization (IRST)Chitosan Surface AnalysisSlide 15Biopolymer Functionality and LocalizationSlide 17Selective, Voltage-Programmable Chitosan DepositionChitosan Deposition and NHS-fluorescein ReactionSpatial LocalizationSpatially Localized Biomolecular ReactionsImmobilization of Biomolecules onto Spatially Patterned Chitosan SurfacesCovalent Coupling of ssDNADNA-DNA HybridizationAnalysis of Purified Total RNA from Escherichia coli culture by Sandwich AssayNucleic Acid Bonding to ChitosanSlide 27Slide 28Slide 29Slide 30Microfluidics SystemsEncapsulated Microfluidic DevicesSlide 33Slide 34Microfluidics PackagingSlide 36Biomolecular Microsystem PackagingSlide 38Slide 39Slide 40Slide 41Real-Time Chemical SensingReal-Time, In-Situ Optical Process MonitorReal-Time, In-Situ Optical CharacterizationDirect Gas and Surface Analysis of Aqueous MicrosystemsRole of Liquid-Gas Coupling MicrodeviceLiquid/Gas Coupling InterfaceGas and Surface Analysis of Aqueous MicrosystemsSlide 49Vacuum-Based Aqueous Sampling01/15/19 1Rubloff - bioscience & bioengineering researchResearch Summary Bioscience and Bioengineering Gary W. RubloffProfessor, Materials Science and Engineering, Institute for Systems Research,and Electrical and Computer EngineeringUniversity of Marylandwww.isr.umd.edu/gwrubloff, [email protected] of MaterialsScience and Engineering01/15/19 2Rubloff - bioscience & bioengineering researchOverview01/15/19 3Rubloff - bioscience & bioengineering researchBiomolecular Microsystems•Bill Bentley - proteins•Greg Payne - biopolymers•Reza Ghodssi - MEMS•Gary Rubloff – materials•Ben Shapiro – microfluidics modeling•Mariano Anderle group, IRST (Trento, Italy) – surface analysis•UMD MRSEC•UMBI (U. Maryland Biotechnology Institute)01/15/19 4Rubloff - bioscience & bioengineering researchMotivationSynergy of bioprocessing, MEMS, and semiconductor process & analysis environments for broad bioscience and biotechnology applicationsSemiconductor macroprocessing & analysisSemiconductor macroprocessing & analysisMEMS technologyMEMS technologyScienceScience- e.g., protein structureTechnologyTechnology-e.g., pharmaceuticals,medicine, forensics, …MEMS-based bioprocess systemMEMS-based bioprocess systemProteinsynthesisProteinsynthesisSeparationSeparationPurificationPurificationProteinproductProteinproductMEMS microsystems for reaction, analysis, and controlSemiconductor processesfor MEMS system fabricationSemiconductor process environmentsfor in-situ conditioning and analysisof MEMS-based bioprocessesBioprocess scale-down for efficiency,cost, and control01/15/19 5Rubloff - bioscience & bioengineering researchBiomolecular Micromanufacturing•Programmable bio-microenvironments for sensing, diagnosis and synthesis of biomolecular entities–Bioprocess leadership now aimed at scale-down•Selective, voltage-programmable deposition & release of biofunctional polymers –Compact films and hydrogels –Subsequent bonding of coupling agents, proteins, ssDNA, mRNA•Interdisciplinary team – proteins/cells, biopolymers, MEMS, semiconductor materials/process, in-situ diagnostics–Merging of biotechnology and micromanufacturing–5 publications in 1st yr of results00.20.40.60.811.21.41.60 0.5 1 1.5 2 2.5 3Voltage (volts)Thickness (microns)Ne gative ElectrodePositive ElectrodeW. Bentley (ChE/UMBI)G. Payne (UMBI)R. Ghodssi (ECE/ISR)G. W. Rubloff (MSE/ISR)3D view of microchannel3D view of microchannelMicrochannel with chitosan andfluorescein deposited on electrodesMicrochannel with chitosan andfluorescein deposited on electrodeselectrodepositionof chitosan biopolymerchitosan biopolymer& fluoresceinchitosan hydrogelmicrofluidicchannel &electrodes01/15/19 6Rubloff - bioscience & bioengineering researchBiomolecular Micromanufacturing•Applications–Cell-to-cell signaling (“quorum sensing”)–Biomolecular sensing and identification–Biomolecule manufacturing on demand•The future is in scale-down of biotechnology to MEMS-level systems, but …•Understanding and optimizing biomolecular micromanufacturing is a major challenge–High surface/volume ratio–Sensing, characterizing, controlling internal microenvironments01/15/19 7Rubloff - bioscience & bioengineering researchBiopolymer Deposition01/15/19 8Rubloff - bioscience & bioengineering researchElectrodeposition ofChitosan Biopolymer•Amine group biofunctionality•Electrodeposition  voltage programmable biofunctionality in biomicrosystemsElectric-field Driven Deposition of ChitosanChitosan SolutionDC Power SupplyNH3NH3NH3NH2Deposition of Chitosan on Cathode Surfacein Response to an Applied Voltage• Electrostatic property and pH – dependent solubility allow chitosan to be deposited onto the surface of a negative electrode (cathode) in response to an applied voltageChitosan as an Interface MaterialProperties of Chitosan• Cationic Polyelectrolyte • pH-dependent Solubility • Nucleophilic Reactivity • Surface Wettability • Biocompatible and BiodegradableDecalcificationDeproteinationDeacetylationChitosan is an amine-rich polysaccharide.01/15/19 9Rubloff - bioscience & bioengineering researchSolution Properties and Electrodeposition•Electrodeposition at negative electrode due to NH3+ at low pHsoluble at low pH insoluble at high pH OOHHOOOOHHOOnnOOHHOOOOHHOO+ 2n H+NH3+NH3+NH2NH200.20.40.60.811.21.41.60 0.5 1 1.5 2 2.5 3Voltage (volts)Thickness (microns)Negative ElectrodePositive Electrode•pH-dependent solubility (pKa = 6.3)•H2 evolution and locally high pH at deposition site–Compact film or hydrogel•Subsequent high pH stabilizes chitosan film•Subsequent low pH dissolves chitosan film unless surface passivated01/15/19 10Rubloff - bioscience & bioengineering researchChitosan: Hydrogels & Compact FilmsHydrogelHydrogels in Micro-scale Systems• Three-Dimensional StructuresMicro-fluidic Channels, Barriers and Valves• Aqueous MicroenvironmentBiocompatibleAverage Water Content of theHydrogel = 97.916 ± 0.005 %Experimental Conditions: 1.5 % w/w ChitosanCurrent density = 20