Technology and sustainability hand in hand in the final of the Fraunhofer Portugal Challenge 2022

(2^nd) Catarina Sousa | Bioremediation of agro-industrial effluents mediated by microalgae

Every year, large amounts of agro-industrial effluents are produced all over the world and its sustainable management is still a technological challenge. This thesis addresses the remediation of four agro-industrial effluents (aquaculture, cattle, swine, and poultry) and an industrial effluent (landfill leachate) by treatment with biomass ash and microalgae. The pre-treatment with biomass ash allowed the partial precipitation of total solids, reduction of the turbidity and microbial load of the effluents, resulting in a partially treated effluent and a precipitate rich in mineral and organic components.
The torrefaction of algae biomass and its mixtures with lignocellulosic biomass made it possible to obtain biochars with potential for energy recovery, use as biostimulants for seed germination, or as adsorbents for cationic pigments. The work carried out allowed to demonstrate the feasibility of treating the studied effluents by chemical precipitation and bioremediation with microalgae and to suggest different ways of valuing the solid by-products generated.
The use of microalgae in the treatment of the tested agro-industrial and industrial effluents proved to be very promising, namely using simple pre-treatments with ash, making it possible to obtain biomass with excellent characteristics for integration in animal feed or crop fertilization. The use of different wastes becomes essential in a sustainable approach to the development of a circular economy.

(2^nd) Inês Cunha | Finding Inspiration in Nature Towards Sustainable Development
The unsustainable model used for developing electronic devices has led to an increase in the overharvesting of natural resources and electronic waste (e-waste) generation. Thus, “greener” materials and low-cost, scalable fabrication processes compatible with roll-to-roll principle, such as printing/ coating techniques, are vital for creating new-concept systems that can be made massive and serve the Internet-of-Things. The resulting devices and systems are expected to be energy efficient, assume different form factors and be compliant with mechanical deformations, and be easily repaired and recycled. One of the best alternative materials to face the zero e-waste challenge is cellulose, the most abundant and renewable biopolymer resource on Earth, and the main component of paper. Inês Cunha and her team’s approach consists of a new generation of reusable, healable and recyclable regenerated cellulose-based hydrogel stickers. They are prepared from a simple, fast, low-cost, and environmental-friendly aqueous alkali salt/urea dissolution method of cellulose, combined with carboxymethyl cellulose to improve the hydrogel’s robustness, and subsequent regeneration with acetic acid. The developed hydrogel membranes have high ionic conductivity, reasonable transparency, a soft and sticky surface, and can be easily molded as plasticine, and thus applied “on-the-fly”, through a “cut, peel and stick” process. They can be reused and easily repaired through gentle pressing on the separated interfaces when mechanically damaged. Such unique features are attractive for application in sustainable, low-power, ion-controlled electronics, such as electrolyte-gated transistors (EGTs) and circuits. To explore the full potential of the hydrogels for this application, their group also designed and formulated a water-based, screen-printable ink loaded with zinc oxide semiconducting nanostructures that does not need any sintering process, being compatible with conventional office paper.

(3^rd) Sirazul Haque | Optically thick but electrically thin solar cells: For portable and flexible electronic applications
The path to achieve highly efficient, ultra-thin perovskite solar cells (PSCs) demands the use of advanced optical management techniques that can significantly boost cell absorption, thus offsetting the common losses expected from thinner absorber layers.
Sirazul and his team developed and studied two novel photonic concepts, acting in the wave-optics regime, and applied them to PSCs with distinct thicknesses of the perovskite absorber (250-500 nm). Firstly, front-located photonic-structured electron transport layers (ETLs) were studied, demonstrating the best photocurrent improvement relative to unpatterned cells (up to 27% - value close to the fundamental Lambertian limit). Secondly, PSCs conformally deposited on rather industrially-favorable photonic-structured substrates show also a comparable photocurrent enhancement to the previous structure (up to 25%) including a significant omni-directional optical response for angles up to 70 degrees.

(1^st) Giovanna Calvão | Fluorescence-based biosensor for detection and quantification of Colletotrichum acutatum in infected olives

Sustainable production of different staple agricultural crops is currently threatened by plant pathogens, resulting in high economic losses and severe yield reduction, not only due to losses in primary production but also to post-harvest product waste during storage. This is especially damaging for smallholder farmers and low-income countries.
Anthracnose is a fungal disease caused by a wide variety of Colletotrichum species, regarded as one of the most common and globally distributed diseases in agricultural crops. This pathogen is a primary concern for olive production, and several species have been associated with disease outbreaks in the many olive growing regions.
The main goal of this thesis was to develop a novel high-throughput and cost-effective sensing platform for olive anthracnose detection, one that could tackle the issues of other existing technologies, which are laborious and time consuming. New sensing approaches should provide a simple and early diagnosis, even before the first visible symptoms appear. The presented approach combines three main components – DNA technology, biosensors and nanomaterials. The referred sensor is an optical-based biosensor, and it was designed using a fluorescence technique that incorporates fluorescent nanoparticles functionalized with DNA probes.

(2^nd) Bárbara Tavares | A Cluster-Based Trip Prediction Graph Neural Network for Bike Sharing Systems
Bike Sharing Systems (BSSs) are emerging as an innovative public transportation service. Ensuring the proper functioning of a BSSis crucial, given that these systems are committed to eradicating many of the current global concerns, by promoting environmental and economic sustainability, and contributing to improving the life quality of the population. Strategies for bicycle rebalancing become important and for this, bicycle traffic prediction is essential, as it allows to operate more efficiently and to react in advance.
In this work, it is proposed a bicycle trips predictor based on Graph Neural Network embeddings, taking into consideration station groupings (according to some clustering techniques), meteorology conditions, geographical distances, and trip patterns.

(3^rd) Leandro Rodrigues | Leveraging vegetables production with Robotics, Artificial Intelligence and Computer Vision
The evolution of agricultural research, scientific and technological advances in robotics, computer vision and Artificial Intelligence allows the development of increasingly precise operations. In what concerns plant growth monitoring, it is possible to evaluate, in an automatic way and in real-time, the characteristics of the plants, mainly those presented as a result of the dynamic interaction between the genetic component and the environment. In this work, a robotic prototype with Computer Vision was developed. This cartesian robot prototype is equipped with optical sensors for autonomous and dynamic in situ image capture of plants and soil. This information has application in phenotyping plant characteristics to inform agricultural practices.
The developed robotic platform together with the collected and processed information may have different applications of phenotyping (namely in the support of cultural operations), sensor testing, a strong pedagogical component, among others.