Department of Chemistry and Materials Science

Microfabrication

The group develops micro- and nanofabrication processes for applications in fluidic, chemical, biological, mechanical and thermal devices.

Our research areas:

Micro- and nanofabrication
Microfluidics and wetting
Coatings and surface treatments

We employ a wide range of micro- and nanofabrication tools at Aalto Nanofab to create structures, devices and surfaces for fluidic, thermal, and biological applications. We have projects on neurons-on-a-chip (MEAs, carbon microelectrodes, dopamine analysis), carbon-MEMS (pyrolytic SU-8), superhydrophobic surfaces (blood repellency, icephobicity, antifouling and oleophobicity), foam materials (thermal insulation), single cell trapping (patterned superhydrophobic surfaces), flexible devices (metallization of elastomers).

Materials we work with:

Silicon (bulk and SOI), Pyrex, Kapton, Aluminum as substrates
AZ positive resists (also with image reversal), SU-8 and NXT15 negative resists
PDMS and thiolenes for replica moulding
Plasma Teflon and spin coated CYTOP for hydrophobic coatings
SAMs made by wet and dry techniques
Plasma deposited carbon materials (DLC, nc-C, ta-C)
UV-sensitive sol-gel materials (SiO2, Al2O3)
ALD films: TiO2, SiO2, Al2O3, TiN, NbN, Pt, nanolaminates
Metals (Al, Cr, Cu, W, Pt) by sputtering and evaporation

Cu-PDMS superhydrophobic with 5 liquids

PolarR

Radial arrays

Korea NC MEA

MEA pillars schematic 3D

MicroPESI and coin

Nebulizer chips packaged

Serif-T mushrooms

SU-8 ESI array with coin

Wafer with SU-8 separation chips

Woodpile of PLA

ZnO ALD coated AAAO

Our work at Micronova cleanroom

We work on silicon, glass and polymer technologies, utilizing the Micronova cleanroom. Micronova is the largest research cleanroom in northern Europe with its 2600 m2 of class 10-class 1000 space, shared between VTT and Aalto University. Micronova is equipped with a wide range of processing tools for MEMS, CMOS, III-V and polymer technologies.

Examples of our equipment:

optical lithography with backside alignment (Süss MA-6)
DRIE (Oxford 100 cryo and STS Bosch) and RIE (Oxford 80)
PECVD (Oxford 80)
ALD (Picosun R200 and Beneq TFS 500 thermal and Beneq TFS 500 plasma)
sputtering (various tools) and evaporation (various tools)
Centrotherm tube furnaces (thermal oxidation, LPCVD poly, LPCVD nitride)
AML bonder/nanoimprint

For a complete list of equipment, see: http://www.micronova.fi/nanofabrication_centre-002/equipment/

Research group members:

New funding to commercialise high-tech liquid-repelling coatings

New funding to get damage-resistant, liquid-repelling surfaces out of the laboratory and onto solar panels, skis, and more

Taiteellinen kuva panssaroidusta superhydrofobisesta pinnasta, joka kestää iskuja ja hylkii nesteitä tehokkaasti. Kuva: Juha Juvonen.

To measure or not to measure? The basics of academic thinking provide students with problem-solving skills

Students of technology learn at an early stage of their studies that there may be various functional solutions to a single problem. Learning the skill to justify solutions scientifically is an integral part of the Master of Science in Technology education.

New method enables the recovery of trace platinum concentrations

Renewable energy and electric traffic will increase the need for critical metals. Even the smallest quantities of metal must be recovered.

Platinalla pinnoitettu hiilipala / Kuva: Petteri Halli

The toxicity of nanoparticles and their interaction with cells: an in vitro metabolomic perspective

Mohammad Awashra, Piotr Mlynarz 2023 Nanoscale Advances

Superhydrophobic Copper-Composite Surfaces Exert Antibacterial Effects against Gram-Negative and -Positive Bacteria

Seyed Mehran Mirmohammadi, Kirsi Savijoki, Sasha Hoshian, Pekka Varmanen, Jari Yli-Kauhaluoma, Ville Jokinen, Sami Franssila 2023 Advanced Materials Interfaces

Microalgae Chlorella vulgaris and kraft lignin stabilized cellulosic wet foams for camouflage

Nina Forsman, Tia Lohtander, Juha Jordan, Ngoc Huynh, Ari Seppälä, Päivi Laaksonen, Sami Franssila, Monika Österberg 2022 Soft Matter

Lightweight lignocellulosic foams for thermal insulation

Tia Lohtander, Reima Herrala, Päivi Laaksonen, Sami Franssila, Monika Österberg 2022 Cellulose

Doping Colloidal Quantum Dot Materials and Devices for Photovoltaics

Lingju Meng, Xihua Wang 2022 Energies