Research by FCT NOVA, shared with students and researchers from Técnico’s Campus Tecnológico e Nuclear, explores bio-inspired solutions for developing sustainable materials that are adaptable to the environment.
Researcher José Malta, from NOVA School of Science and Technology (NOVA FCT) of NOVA University Lisbon, presented the results of a study that seeks to replicate natural mechanisms to create cellulose-based materials capable of reacting to humidity and collecting water from the air, in the auditorium of Campus Tecnológico e Nuclear (CTN) of Instituto Superior Técnico.
The seminar, promoted by Academia C²TN – Centro de Ciências e Tecnologias Nucleares, took place on the 31st of October and featured an introduction to the speaker by C²TN researcher António Pereira Gonçalves.
Entitled ‘Nature-inspired Cellulose Networks for Moisture Sensing,’ the session addressed how observing natural phenomena—such as those found in plants or certain insects—can inspire new material systems. José Malta highlighted the role of cellulose, the most abundant biopolymer in nature, in creating smart and sustainable materials capable of changing shape or colour when exposed to water. Practical applications of these systems in smart textiles, environmental sensors, biomedical devices and soft microrobotics were also discussed.
“We want to capture water from the air in a simple and efficient way, without consuming energy, drawing inspiration from nature to combat the water scarcity that affects millions of people,” explained José Malta, emphasising the importance of passive and ecological solutions to respond to global sustainability challenges.
The research, carried out as part of the ´DynaCellCollect` project, seeks to replicate natural biological mechanisms, such as those found in spider webs or the Namib Desert beetle, which capture water droplets from the air. These principles have been applied to the development of cellulose films and fibres with hygromorphic behaviour, materials that detect the presence of moisture and convert it into mechanical movement, thus functioning simultaneously as sensors and actuators.
During the session, José Malta emphasized one of the most innovative results of the work: the reproduction of the movement of Erodium plant stems using cross-linked hydroxypropylcellulose (HPC) films, which roll up and unroll depending on changes in humidity.
‘When exposed to water, the films behave similarly to plant stems, which allows them to be used as humidity sensors in a controlled manner,’ said the researcher.
The research team at the Materials Research Centre (CENIMAT/i3N) at NOVA FCT also observed that adding lignin — another natural compound found in plants — to double-layer cellulose acetate fibres increases water uptake capacity, demonstrating that combining different natural materials can improve the performance of these systems.
“These materials can be used in smart textiles, environmental sensors or biomedical devices, and represent an important step in creating sustainable solutions inspired by biology,” added José Malta.
This interdisciplinary approach falls under the C²TN ‘Advanced Materials’ Thematic Line, dedicated to the development of functional, energy-efficient and sustainable materials with an impact on the environment, energy and health.
Despite the promising results, the researcher acknowledges that the path to industrial application remains challenging.
‘The big challenge is to make these materials more efficient and commercially viable, while maintaining their sustainability,’ said the researcher, adding that he hopes ‘to be able to compete with existing synthetic materials, but in an environmentally friendly way.’
At the end of the session, José Malta left a message for the audience:
“The solutions to many of our problems are already around us. Nature provides us with answers; it is up to us to interpret them and apply them to technology and science”.