Microreactors: materials, fabrication, catalysis sami.franssila@aalto.fi

Microreactor Tiggelaar PhD thesis, Twente

Microreactors Small volume good if expensive and/or dangerous chemicals Fast reactions because small diffusion distances Large surface area (either positive or negative effect) Good temperature control and fast ramp rates Good flow control because of laminar flow Besser: J. Vac. Sci. Technol. B 21.2., Mar/Apr 2003

Silicon microreactors Uniform temperature due to high thermal conductivity of silicon (also due to small dimensions of microstructures). This is beneficial because it prevents hot spot creation, and enables highly exothermic and explosive reactions to be studied safely.

Microhotplate (1) Sensors and Actuators B 68 Ž2000. 223–233

Microhotplate (2) Sensors and Actuators B 68 Ž2000. 223–233

Linear microreactor R.M. Tiggelaar et al. / Sensors and Actuators A 119 (2005) 196–205

A comprehensive article P Knapkiewicz: The silicon–glass microreactor with embedded sensors—technology and results of preliminary qualitative tests, toward intelligent microreaction plant, J. Micromech. Microeng. 23 (2013) 035014 (10pp) doi:10.1088/0960-1317/23/3/035014

Overview J. Micromech. Microeng. 23 (2013) 035014

J. Micromech. Microeng. 23 (2013) 035014

Continuos fluid + droplets J. Micromech. Microeng. 23 (2013) 035014

J. Micromech. Microeng. 23 (2013) 035014

J. Micromech. Microeng. 23 (2013) 035014

High pressure reactor Tiggelaar

A single reaction spot J.Micromech.Microeng. 2011

Droplet movement

Digital microreactor

Multiphase flow Javier Atencia & David J. Beebe

Droplet reactors Cells or microbeads are separated from each other by oil plugs. In theory, thousands of droplets/minute = thousands of replicates of your experiment Javier Atencia & David J. Beebe

Thermal isolation Silicon is good because high thermal conductivity ensures uniform temperature Silicon is bad because heat spreads efficiently and local heating is impossible Black area = silicon wafer White = etched area

Heated nebulizer chip (1) Nebulizer gas enters from a thru-wafer via-hole P. Östman, Lab. Chip., 2006, p948 P. Östman, Anal.Chem. 2006, p. 3027 S. Franssila, J.MEMS 2006, p. 1251

Heated nebulizer chip (2) Saarela et al, 2007

Glass microprocessing Ville Saarela et al., µTAS 2006, Tokio

Thermal isolation, LC

Gradient generator Langmuir 2000, 16, 8311-8316

Lamination mixing

Radiolabeling synthesis Quake et al: Radiolabeled Imaging Probe Using Integrated Microfluidics

Radioactive labeling reactor Quake et al: Radiolabeled Imaging Probe Using Integrated Microfluidics

Buried channels (1) Top: mask layout (1–3) sealable channels; (4) gradually varying depth design; (5) unsealable mask window for access holes or nano-scale holes in the oxide layer; (6) non-uniform channel. J. Micromech. Microeng. 20 (2010) 045013 (8pp) doi:10.1088/0960-1317/20/4/045013

Buried channels (2)

Fluidic connectors Fluidic connectors Ville Saarela, TKK

Reactor packaging J. Micromech. Microeng. 23 (2013) 035014

The complete system J. Micromech. Microeng. 23 (2013) 035014

On-the-spot 4 topics, 4 groups of ca. 4 people 25 min to study the article 4*5 min short talks to explain key features: -materials/surfaces & compatibility -fluid flow: pumping and valving -thermal characteristics -sensors-detectors

1. TiO2 photocatalytic J. Micromech. Microeng. 25 (2015) 025006

2. Nanoparticle synthesis small 2014, 10, No. 6, 1076–1080

small 2014, 10, No. 6, 1076–1080

3. Catalytic microreactor Chemical Engineering Journal 135S (2008) S317–S326

4. PDMS-glass synthetic reactor Lab Chip, 2002, 2, 197–202

Lab Chip, 2002, 2, 197–202