Material can be trained like a Pavlov dog – Professor Olli Ikkala and his team develop new materials

The sharpest tip of materials science is coming up with answers to questions such as can materials ‘learn’ new properties or how to keep a cancerous tumour alive outside the body.
Olli Ikkala ryhmäkuvassa portaikossa viiden tutkijan kanssa, Ikkala seisoo portaikon edessä ja katsoo tutkijoita, tutkijat seisovat rappusilla peräkkäin.
Pictured, from left, Olli Ikkala, Zhongpeng Lyu, Hang Zhang, Sebastian Löscher, Bo Peng and Nonappa. Photo: Jaakko Kahilaniemi.

Professor Olli Ikkala’s research draws in scientists from across many fields, including physics, chemistry, and biomedicine to develop new materials that have properties derived from nature.

Working with Olli

‘After being at Aalto for several months, my supervisor was retiring, so I needed a new host group to continue my research on MXenes, a type of 2-dimensional material. Olli’s group appealed to me because it has a well-equipped lab for material synthesis and the research topics were also very interdisciplinary. This was before the pandemic, so I went directly to his office to chat with him. Interestingly, he has his Chinese name card at his door. Clearly, I was not the first Chinese person looking for him.

I had never expected my MXene project to have been so interesting to him. It turns out that his knowledge in many different fields enabled him to find common interests from different projects. I then became one of his group members and continued my research. By becoming part of the HYBER project that he was the head of, I have been able to build new collaborations with people across different fields, and my research topic was largely extended.

Even during the pandemic, Olli has made sure that we’ve been able to safely collaborate, organizing online meetings and an outdoor barbeque at his summer cottage for group members. A former colleague of mine in Stockholm University had Olli as her opponent on her thesis defense. She said Olli’s questions were sharp and precise and had really enjoyed having him as a thesis opponent. Everyone in our field in Nordic countries knows of him, he has been a great supervisor to have.’

  • Dr. Zhongpeng Lyu, Postdoctoral Researcher, Aalto University

Giving gels Pavlovian memory to ‘learn’ a new behaviour

‘I research materials that can be made to behave in a conditioned way, i.e., to mimic simplistically psychological learning. The classic example of conditioning is Pavlov’s dog — the dog would salivate when shown food, but not when ringing a bell. However, if the dog would hear a bell when it was shown food, the “conditioned” dog would salivate at the sound of the bell, even without food.

We wanted to make materials that mimic this learning behaviour, and set about trying to recreate conditioning in a soft polymer. We succeeded, by making a gel that consists of water and polymers. Initially the gel melts when heated but not upon shining light. It can be conditioned to melt when light is shone upon it. The gel has nanosized particles of gold mixed in, and when the light is shone on it normally, nothing happens. But if it is heated to its melting point whilst this light is shining on it, the gel becomes conditioned. This means that the next time the light is shone on it, it spontaneously melts, even if it’s not being heated from the outside.

The mechanism behind the conditioning in the material is that, when both heating and light are applied, the gold nanoparticles rearrange into chains that start to absorb the light in a new specific wavelength range. Once light shines again on the gel, the assembled nanoparticles themselves heat it up, melting it from the inside. People have been able to make electronic systems behave like Pavlov’s dog, but this is the first time for a soft material to do this “trick”. Importantly, the gel behaviour follows the same logic diagram as the Pavlov dog experiment. We are generalising the conditioning concept for other properties to make progressively “life-like materials”, perhaps even as a new simplistic form of artificial intelligence.’

  • Dr. Hang Zhang, Postdoctoral Researcher, Aalto University

Personalized breast cancer models using nanotechnology

‘Breast cancer is the most frequently diagnosed cancer type, and is one of the leading causes of cancer-related deaths in women. In Finland, it represents nearly 30% of all cancer with more than 5 000 new annual cases.

Despite tremendous progress in cancer-related research, the existing one-size-fits-all treatment has the least success rate when it comes to breast cancer. To address this challenge, the research group of Professor Juha Klefström, a top cancer biologist from the University of Helsinki, joined their forces with Olli’s group to develop personalized breast cancer therapy. The goal was to develop materials that mimic the cellular environment of breast cancer tissues. The aim is to keep the surgically removed patient-derived tumor tissues alive for weeks under laboratory conditions, without losing their biological and physicochemical properties.

Validated using more than 2 000 patient samples, our technology is one of the significant breakthroughs in cancer biology in general and breast cancer in particular. Our research has resulted in two Business Finland-funded commercialisation projects aiming at precision cancer treatment.

We created cost-effective nanoscaffolds with tunable mechanical and functional properties. Our scaffolds allow predictive and long-term storage of patient tissues offering a unique platform for identifying drug response of each patient and can be individually modeled.’

  • Nonappa, Associate Professor at the Tampere University, Adjunct Professor at Aalto University

Delivering drugs to the right part of the body

‘Advanced therapy medicines — such as mRNA and protein treatments are becoming popular at the moment — not least because the use of mRNA in some of the covid-19 vaccines. As part of the GeneCellNano flagship project, that Olli is a member of, I am researching using polymers to make targeted drug delivery for conditions in the eye.

With treatments like vaccines, it doesn’t exactly matter where in the body the chemical you inject ends up, because the immune system will find them and respond to them. But for targeted treatments it does. For example, if you’re treating a condition of the eye, it’s not useful if the drug you inject ends up in the feet. Our research is developing materials that can transport the drug safely within the target area, like the eye, and then release it only where it is needed.

As a chemist, once you start working with medical research you receive a long list of requirements of what your material must and must not do, and it can sometimes feel overwhelming to achieve all the parameters. This is why I am fortunate to work in the MolMat Lab, since Olli always has supportive ideas for every kind of problem. In fact, he is one of the most creative minds I have met so far. You can have a ten-minute talk with him and you have three new ideas at the end to go and try.’

  • Dr. Sebastian Löscher, Postdoctoral Researcher, Aalto University

Making magnetic sensation for future robots

‘Biologists know that animals like birds and turtles that navigate across huge distances can do this by sensing earth’s magnetic fields, but don’t know sufficiently how animals sense magnetism. We wanted to see if we could create bioinspired magnetic sensing using our materials and whether we could achieve material behaviours that resemble simple learning processes, i.e., sensitisation and habituation.

To make a material that can sense magnetic fields, we partially fill a gap between two electrodes with magnetic nanoparticles. In its normal state, electricity cannot flow through, so there’s almost no conductivity between the electrodes. When the device is exposed to a magnetic field, the particles form into chains, bridging the gap between the electrodes, creating a current we can measure. This increase in conductivity is how we know the device has detected a magnetic field.

We are only looking into the fundamental principles of materials that can sense, but future applications are possible to imagine, specifically in fields like soft robotics. The ideal materials for soft robotics can sense their surroundings — like if something is magnetic — and can then react to what they sense.’

  • Dr. Bo Peng, Academy Research Fellow, Aalto University
Professori Olli Ikkala katsoo kameraan, on pukeutunut vaaleaan pikkutakkiin ja farkkuihin, seisoo vaaleassa aulassa, taustalla portaikko. Kuva: Jaakko Kahilaniemi.
Olli Ikkala is well networked. Sometimes new research directions get started when he receives phone calls in unexpected places. Photo: Jaakko Kahilaniemi.

Olli Ikkala

  • Started his careerat the Low Temperature Laboratory of the former Helsinki University of Technology. He completed his Master's in 1977 and defended his doctoral thesis in 1982.
  • Also made a career in the private sector, mainly at the Neste research centre, researching polymer physics and batteries for storing solar energy in the mid-1980s. He accidentally came across polymeric nanotechnology at the turn of the 1980s and 90s as part of an effort to commercialise electrically conducting polymers.
  • Two-time recipient of prestigious Advanced Grant funding from the European Research Council, each worth €2.5 million. Appointed by the Academy of Finland, he served as an Academy Professor for two periods and has also led a national centre of excellence for five years. He has published 326 peer-reviewed scientific articles during his career that have been referred to nearly 22 000 times and has been a thesis advisor for 35 doctoral dissertations. Received the prestigious Humboldt Research Award recently.

Is also

  • Well networked. Sometimes new research directions get started when receiving phone calls in unexpected places. Since the early 1990s, he has been receiving co-operation offers in relation to biotechnology, nanocellulose, cancer research, and programmable materials. The latest such call Ikkala responded to at his summer cottage in 2020, when Professors Seppo Ylä-Herttuala and Arto Urtti reached out asking him to join a flagship project on biological medicine.
  • Organist. Ikkala played the organ at Sibelius Academy's youth department during his school years and later privately completed the professional organist course at Sibelius Academy. When younger, he was an active organist at several Helsinki churches. However, when his academic career took off, there was less time for commuting to churches for practise. Today, new technology has enabled virtual organs with an accurate keyboard feel and completely authentic sound. He now plays a virtual instrument at home, which mimics the Saint-Maximin-la-Sainte-Baume organ in Provence, France, built in 1772.

Read more about the personalized breast cancer models:

Breast cancer tissue in a culture model in which hormone receptors disappear (left) and within the culture model developed in this study which maintains the hormone receptors (right). The hormone receptors are indicated in green. Photo: Pauliina Munne.

Finnish researchers developed mini-breast cancer as a new weapon against the most common type of breast cancer

Breast cancer researchers from the University of Helsinki and material scientists from Aalto University have jointly developed a gel-grown “mini-breast cancer” that will help uncover more effective treatments against hormone-dependent breast cancer.


Text: Matthew Allinson and Tiina Aulanko-Jokirinne
Photos: Jaakko Kahilaniemi

This article was published in the Aalto University Magazine issue 29, October 2021.

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