Reactive Inkjet Printing. Patrick J. Smith University of Sheffield

Transcription

1 Reactive Inkjet Printing Patrick J. Smith University of Sheffield 15 th November 2017

2 Sheffield Applied Inkjet Research Lab Here we are! Main Research themes Tissue engineering Reactive Inkjet Printing Printed Electronics Inkjet & Composites

3 Overview Exploiting inkjet s advantage reactive inkjet printing Printing silk structures

4 Playing to strengths Inkjet Printing can add a variety of materials to the same layer A 100 office printer handles four types of ink! 124 November, 2017 Patrick.Smith@sheffield.ac.uk

5 Goodbye Mr. Ford Any customer can have a car painted any colour that he wants so long as it is black. Instead of: Why not: 12 November, 2017 Patrick.Smith@sheffield.ac.uk 5

6 Reactive Inkjet Printing Traditional Route R.I.J. Make Nanoparticles Stabilise Nanoparticles Make/Store Ink Make Nanoparticles Make Device Make Device A silver MOD ink generates NPs in-situ, giving % bulk silver conductivity A normal nanoparticle ink gives conductivities of % Macromol. Rapid Commun., 2005, 26, 315 Can we use the same energy for synthesis that we use for patterning? 12 November, 2017 Patrick.Smith@sheffield.ac.uk 6

7 Reactive Inkjet Printing Spin-coat first layer then print second reagent Inkjet first layer then print second reagent Side view Of course, one can inkjet print more precise patterns Plan view 12 November,

8 A Great RIJ Example RIJ = reactive inkjet printing Schematic of selective emitter solar cell structure fabricated using the direct patterned etching method. Direct patterned etching of silicon dioxide uses inkjet to deposit an inactive etching component onto a water soluble surface layer formed over the silicon dioxide. The inactive component reacts with the surface layer, where it contacts, to form an active etchant which etches the silicon dioxide under the surface layer to form a pattern of openings. The method involves fewer steps, lower chemical usage and generates less hazardous chemical waste. A. Lennon et al. Solar Energy Materials & Solar Cells 93 (2009)

9 What can we do with an inkjet printer? We can tailor droplet size We can position the droplet anywhere we like on the substrate We can print up to four inks Either side by side or on top of each other We can control the evaporation rate By using solvent ratios, and varying inter-droplet drying time 12 November,

10 Inkjet printer in Sheffield (MicroFab 4, piezoelectric DOD) Camera Printhead holder Printhead Droplet

11 Magnetite films by reactive printing

12 Reactants Inks used Iron (II) Chloride and Iron (III) Chloride in water (Ink 1) Sodium hydroxide in water (Ink 2) All reactants loaded in inks to correct stoichiometry FeCl 2 + 2FeCl 3 +8NaOH -> Fe 3 O 4 +8NaCl

13 Magnetite thick film Definitely magnetic!

14 14 Silk

15 Regenerated Silk Fibroin as a Bio-ink for printing A promising method for bio scaffold fabrication. 100 μs 200 μs 300 μs Advantages of Regenerated Silk Fibroin: An FDA approved biomaterial Good biocompatibility, biodegradability, mechanical properties Natural peptides in aqueous solution Insoluble after menthol fixing Better printability than collagen, gelatin, alginate

16 Schematic of Janus silk rocket printing process Gregory et al. Small 2016, 12,

17 Diameter & Height f Optical profiler microscope images of silk dots printed using different concentrations of RSF inks: (a) 10, (b) 20, (c) 30, and (d) 40 mg/ml, respectively. (e) The diameter of the dots plotted against the concentrations of RSF solutions. (f) Height plotted against printed layers.

18 Printing different patterns c d e Images of various printed patterns. a) Lines are produced by adjusting the distance of two adjacent droplets. (b) SHEFFIELD ENGINEERING logo. (c) A silk worm picture printed on filter paper. (d) Dot arrays. (e) Printed pillars.

19 Characterization of silk particles red arrow PMMA barrier layer Fully active rocket Janus Rocket

20 Effect of blending PEG 400 into Silk/Cat Fully active silk particle without PEG 400 Fully active silk particle with PEG 400

21 Swimming in H 2 O 2 fuel Fully Active Particle Janus Particle 500µm 500µm Type of Particle Average velocity [µm/s] Persistence length [µm] Fully Active 370 ± ± 6 Janus (half active) 510 ± ± 180

22 Directionality of motion controlled via printing Fully active particle (correlation coefficient=0.003) Fully active particle Janus particle (correlation coefficient=0.66) Janus particle

23 Comparison Fully active and Janus Rockets in 2% Serum Solution with 3% H 2 O 2 Fully Active Rocket In 2% Serum with 3% H 2 O 2 Janus Rocket In 2% Serum with 3% H 2 O 2

24 Comparison of Fully active and Janus Rockets swimming in 2% Human Serum with 3% H 2 O 2 fuel Fully Active Rocket In 2% Serum with 3% H 2 O 2 Janus Rocket In 2% Serum with 3% H 2 O 2 600µm

25 Impact & Media attention News: Journal Inside Front Cover Gregory et al. Reactive inkjet printing of biocompatible enzyme powered silk micro-rockets. Small 2016, 12,

26 Single engine spinner Schematic of silk spinner printing Dual engine spinner

27 SEM images of the printed spinners A B C D E F

28 Single & dual engine spinners 0 S 1 S 5 S 10 S 15 S 20 S 0 S 1 S 5 S 10 S 15 S 20 S

29 Type Of Swimmers Average Velocity (µm/s) Velocity A / B (µm/s) Rotation Speed (rpm) Single 680 ± ± 400 / 550 ± Dual 680 ± ± 270 / 1020 ± 220 6

30 H2O2 Concentration- 100 mg/ml 0 S 1 S 5 S 10 S 15 S 20 S

31 Velocity and Rotation Speed data for the silk spinners in different concentrations of H2O2 A B H 2 O 2 Concentration mg/ml Average Velocity (µm/s) Velocity A / B (µm/s) Rotation Speed (rpm) ± 6 90 ± 8 / 80 ± ± ± 13 / 170 ± ± ± 180 / 270 ± ± ± 300 / 900 ± ± ± 800 / 2500 ± ± ± 400 / 3600 ±

32 Printed layers S 1 S 5 S 10 S 15 S 20 S

33 Velocity and Rotation Speed data for silk spinners with different layers Printed layers Average Velocity (µm/s) Velocity A / B (µm/s) Rotation Speed (rpm) ± ± 400 / 1230 ± ± ± 600 / 2100 ± ± ± 800 / 3200 ±

34 Self powered stirrer -100 layers 0 S 1 S 5 S 10 S 15 S 20 S

35 Velocity and Rotation Speed data for selfpowered silk spinners with different layers Printed Layers Average Velocity (µm/s) Velocity A / B (µm/s) ± ± 4000 / ± ± ± 8000 / ± ± ± / ± Rotation Speed (rpm)

36 Silk spinners for micro-stirring 0 s 10 s 20 s 30 s Control 0 s 10 s 20 s 30 s With spinner Control With spinner d / mm Time / s

37 Summary Successfully printed silk inks with different patterns. Printed silk micro rockets that can swim in bio fluids and controlled their trajectory. Printed silk spinners with dual power systems and explored their application in micro stirring.

38 Acknowledgements I d like to thank Collaborators Dr Xiubo Zhao (CBE, Sheffield) Dr Steve Ebbens (CBE, Sheffield) PDRAs Dr David Gregory Dr Yi Zhang PhD students Miss Yu Zhang Funding bodies EPSRC University of Sheffield