The PHOTOTUNE project has resulted in 29 scientific articles that have already gathered ca. 1300 citations. These include, e.g. 4xNature Communications, 5xAdvanced Materials, 1xPNAS, 1xChemical Science, among others. At least six additional PHOTOTUNE-associated publications will be submitted in the becoming months. Our activities have spanned from organic synthesis and materials engineering all the way to soft-matter photonics and soft robotics. The breadth of activities shows up also in the team composition, which throughout the project period has comprised both physicists and chemists. Our works have gained lots of publicity in popular science media (e.g. C&EN, New Scientist, Popular Science, Photonics Media, …) as well as in general newspapers (e.g. USA Today, Daily Mail, in addition to local newspapers and radio interviews).
The most important project outcomes, from the perspective of scientific impact (1.), commercialization (2.) and future openings (3. & 4.) are given below:
1. LIGHT ROBOTICS. We have mainly focused on novel bioinspired photoactuation schemes, demonstrating light-driven materials that are autonomous [Nat. Commun. 2017, 8, 15546], self-regulating [Adv. Mater. 2017, 29, 1701814], programmable [Nat. Commun. 2018, 9, 4148], multi-responsive [Adv. Mater. 2019, 31, 1805985], and capable of advanced functionalities such as swimming [PNAS 2020, 117, 5125], self-oscillation [Nat. Commun. 2019, 10, 5057] and even mimicking simplified forms of learning [Matter 2020, 2, 194].
2. OPTICAL HUMIDITY SENSING. This work started from pure fundamental science but eventually it turned out as the most significant outcome of the project in terms of photonic applications. The fundamental observation [ACS Macro Lett. 2018, 7, 381], based on humidity-dependent photoswitching of polymer thin films, was first developed into a proof of concept device within the ERC PoC funding framework [OPTOSENSE, Agreement No. 789788], which with funding from Business Finland is now being further developed towards profitable business, by a team consisting of both scientists and business developers.
3. PHOTONIC PRINTING. We have developed a device which allows photo-induced inscription/printing of diffractive patterns onto azobenzene-containing thin films with precision that has not been previously achievable. The technique allows us to obtain full-color diffractive images, superpose several holographic structures on top of each other, and inscribe waveguides onto azopolymer films. What's more, all these structures can be erased (either thermally or with light irradiation) and re-written at will, and if needed, used as master gratings and replicated into other polymers such as PDMS. We see great potential in the technique we have developed in e.g. AR/VR technologies and plan to further develop and utilise in it the months and years to come.
4. LIGHT-RECONFIGURABLE CELL-CULTURE PLATFORM. We have shown that similar photosensitive films used in 3. can also be used to control collective migration of epithelial cells and align neuronal axons. This provides an unprecedented reconfigurable tool for cell biologists in creating dynamic platforms for cell culture. Interfacing light-responsive materials with cell biology will be among the key future directions we target in the future.
