The aim of the Nanomicroscopy Center is to promote and produce scientific research and collaboration. The results of these goals are manifested in scientific publications and theses.
Pigment analysis of two unprovenienced fresco fragments from Pompeii – Identifying the Ancient Roman pigment palette
The status of an artist was low in Ancient Rome. Being an artist was unappreciated, difficult and only a handful of their names have survived history. Figuring out the pigment palette of the artist is a way of reading their technique and profession, mirroring the economic and social standards of that time. Most of the pigments can be recognized firstly by knowing the painting technique of the frescoes and secondly by quantitative data. Two fragments of wall paintings from Pompeii were studied at the Nanomicroscopy Center at Aalto University using energy dispersive X-ray spectroscopy at a scanning electron microscope (SEM-EDX). read more...
Tuuli Kasso, tuuli.kasso [at] helsinki [dot] fi
High quality luxury of recent past – ethnographic nettle fabrics revealed in Finland
In her master's thesis to Helsinki University in the field of craft science, Jenni Suomela (MA in education) identified the fibre material of twelve ethnographic textiles from the collections of The National Museum of Finland. The studied objects were dated to the 19th century AD and were determined as plant fibres in visual analysis – but which of the three most common textile bast fibres were they? The surface morphology seen in SEM images of flax (Linum usitatissimum), nettle (Urtica dioica) and hemp (Cannabis sativa) fibres is nearly identical. read more...
Jenni Suomela (2015) Nokkoskuidun tunnistusmenetelmät, Master’s thesis (in Finnish).
Natural mordants, wool and a nettle fibre in a millennia old Finnish textile finds
During the Late Iron Age (800–1300 AD), wool, yarns and fabrics were dyed into red, red-orange, purple, blue and black. The organic colourants were obtained from plants and lichens. Related to the chemical composition of these colourants, three different dyeing methods were needed in dyeing. Using the scanning electron microscopes of the Nanomicroscopy Center in Aalto University, PhD Krista Vajanto discovered in her doctoral dissertation the dyeing methods known by the prehistoric Finns: vat dyeing, mordant dyeing and dyeing with fermented condensed tannins. read more...
Krista Vajanto (2016) Dyes and Dyeing Methods in Late Iron Age Finland, PhD thesis.
Bear and other animal hairs in Late Iron Age burials in Finland
In archaeology, hairs and remains of pelts are found especially in graves where animal skins have been used for clothing, for different kind of purses and bags, and for wrapping the body. Utilizing the facilities at the Nanomicroscopy Center at Aalto University, archaeologist Tuija Kirkinen conducted thus far the most comprehensive study of animal hair in Finland as a part of her doctoral thesis to shed light on the prehistoric human–animal relationship. Over 200 animal hair samples from 110 graves were collected from the Iron Age (800–1300 AD) inhumation burials in southern Finland. read more...
T. Kirkinen, The Role of Wild Animals in Death Rituals: Furs and Animal Skins in the Late Iron Age Inhumation Burials in Southeastern Fennoscandia, Fennoscandia Archaeologica XXXII (2015), p. 101-120.
Patchy proteins make superlattices
Binary nanoparticle superlattices are periodic nanostructures that are typically made from two different types of synthetic material. Such superlattices can, for example, be self-assembled using nanoparticles covered with complementary strands of DNA, but incorporating biological building blocks remains challenging. Mauri Kostiainen and colleagues from Aalto University have now shown that protein cages can be used to form three-dimensional binary superlattices.
Kostiainen, Mauri A; Hiekkataipale, Panu; Laiho, Ari; Lemieux, Vincent; Seitsonen, Jani; Ruokolainen, Janne; Ceci, Pierpaolo, Electrostatic assembly of binary nanoparticle superlattices using protein cages, Nature Nanotechnology (2013) 8, 52-6.
Dancing Magnetic Droplets
Self-assembly is ubiquitous in nature and both functionally and structurally complex structures can be achieved by using equilibrium and non-equilibrium self-assembling process. Timonen et al. from Aalto University have now demonstrated how different states equilibrium and dynamic self-assembly can be trapped and distinguished using ferrofluid droplet on a super-hydrophobic surface.
Timonen, Jaakko V I; Latikka, Mika; Leibler, Ludwik; Ras, Robin H A; Ikkala, Olli, Switchable static and dynamic self-assembly of magnetic droplets on superhydrophobic surfaces, Science (2013) 341, 253-7.
Scientists reach the ultimate goal - controlling chirality in carbon nanotubes
An ultimate goal in the field of carbon nanotube research is to synthesise single-walled carbon nanotubes (SWNTs) with controlled chiralities. Twenty years after the discovery of SWNTs, scientists from Aalto University in Finland, A.M. Prokhorov General Physics Institute RAS in Russia and the Center for Electron Nanoscopy of Technical University of Denmark (DTU) have managed to control chirality in carbon nanotubes during their chemical vapor deposition synthesis.
See the growth in video: https://www.youtube.com/watch?v=ai7N84r-rnQ
He, Maoshuai; Jiang, Hua; Liu, Bilu; Fedotov, Pavel V; Chernov, Alexander I; Obraztsova, Elena D; Cavalca, Filippo; Wagner, Jakob B; Hansen, Thomas W; Anoshkin, Ilya V; Obraztsova, Ekaterina A; Belkin, Alexey V; Sairanen, Emma; Nasibulin, Albert G; Lehtonen, Juha; Kauppinen, Esko I, Chiral-selective growth of single-walled carbon nanotubes on lattice-mismatched epitaxial cobalt nanoparticles, Scientific Reports (2013) 3, 1460.
Spot-welding graphene nanoribbons atom by atom
Researchers at Aalto University in Finland and Utrecht University in the Netherlands have demonstrated the ability to create single atom contacts between gold and graphene nanoribbons. "We cannot use alligator clips on the atomic scale. Using well-defined chemical bonds is the way forward for graphene nanostructures to realise their potential in future electronics," says Professor Peter Liljeroth who heads the Atomic Scale Physics group at Aalto University.
vander Lit, Joost; Boneschanscher, Mark P; Vanmaekelbergh, Daniël; Ijäs, Mari; Uppstu, Andreas; Ervasti, Mikko; Harju, Ari; Liljeroth, Peter; Swart, Ingmar, Suppression of electron-vibron coupling in graphene nanoribbons contacted via a single atom, Nature Communications (2013) 4, 2023.
All-carbon integrated circuits realized
Researchers from Aalto University in Finland and Nagoya University in Japan have realized the first integrated circuits created fully from narbon nanotubes. The developed integrated circuits employ active channels and passive elements fabricated completely from stretchable and thermostable assemblies of carbon nanotubes, with plastic polymer dielectric layers and substrates.
Sun, Dong-Ming; Timmermans, Marina Y; Kaskela, Antti; Nasibulin, Albert G; Kishimoto, Shigeru; Mizutani, Takashi; Kauppinen, Esko I; Ohno, Yutaka, Mouldable all-carbon integrated circuits, Nature Communications (2013) 4, 2302.
How slippery are water-repellent surfaces?
Researchers from Molecular Materials and Soft Matter and Wetting group at Aalto University have measured the low but non-zero friction of droplets moving on slippery water-repellent surfaces.
In a recent article published in Nature Communications by Timonen et al., a water droplet containing magnetic nanoparticles was placed on a water-repellent superhydrophobic surface and observed its oscillation in a magnetic field. The oscillation amplitude of the droplet decreases, as caused by the friction between droplet and surface. By modelling of the droplet motion, it was possible to extract information on the friction and kinetic energy dissipation.
Link to video:http://www.youtube.com/watch?v=76hzbbRYms0
Timonen, Jaakko V I; Latikka, Mika; Ikkala, Olli; Ras, Robin H A, Free-decay and resonant methods for investigating the fundamental limit of superhydrophobicity, Nature Communications (2013) 4, 2398.