Cancer is one of the main causes of death in the world and its incidence increases every
day. Current treatments are insufficient and present many breaches. Hyperthermia is an old
concept and was early established as a cancer treatment option, mainly in superficial
cancers. More recently, the concept of intracellular hyperthermia emerged wherein magnetic
particles are concentrated at the tumor site and remotely heated using an applied magnetic
field to achieve hyperthermic temperatures (42-45ºC). Many patents have been registered in
this area since the year 2000. This chapter presents the most relevant information organized
in two main categories according to the use or not of nanotechnology.

Cellulose and chitin are the two most abundant natural polysaccharides. Both have a semicrystalline microfibrillar structure from which nanofibres can be extracted. These nanofibres are rod-like microcrystals that can be used as nanoscale reinforcements in composites due to their outstanding mechanical properties. This chapter starts by reviewing the sources, extraction methods and properties of cellulose and chitin nanofibres. Then, their use in the fabrication of structural and functional nanocomposites and the applications that have been investigated are reviewed. Nanocomposites are materials with internal nano-sized structures. They benefit from the properties of the nanofillers: low density, nonabrasive, nontoxic, low cost, susceptibility to chemical modifications and biodegradability. Diverse manufacturing technologies have been used to produce films, fibres, foams, sponges, aerogels, etc. Given their natural origin and high stiffness, these polymers have attracted a lot of attention not only in the biomedical and tissue engineering fields but also in areas such as pharmaceutics, cosmetics, agriculture, biosensors and water treatment.

Microporous materials highly activated and with potential to be used as adsorbents in many applications for gas
separation/purification are usually available as powders. These solids usually have a great and reversible gas
uptake, high gas selectivity, good chemical and thermal stability, but are unsuitable to be used in gas adsorption
processes, such as Pressure Swing Adsorption (PSA) or Simulated Moving Bed (SMB).
Zeolites, carbons and more recently metal-organic frameworks (MOFs) are examples of those materials. Their
use in adsorption-based processes are dependent of their upgrading from powders (micrometer scale) to
particles (pellets, spheres or granules at millimeter scale). This would overcome large pressure drops and
consequent energy consumptions when packing adsorbent columns in those processes. Thus, shaping
adsorbents is an important step to use them in industry, although it greatly affects their capacity and selectivity
towards a specific gas separation.
In this work, we explore techniques to shape powdered adsorbents, followed by their textural and mechanical
characterizations, and the study of their adsorption properties towards the main components of post-combustion
flues gases (CO2 and N2). Materials densification is proposed by employing two approaches:
- Conventional shaping through binderless mechanical compression and binder-containing extrusion; and
- Formulation by 3D printing (or additive manufacturing) to produce packed bed morphologies that
precisely replicate computer aided design (CAD) models.
Porous separation media are important for fluid-solid contacting in many unit operations, including adsorption.
Due to practical limitations, media particles are typically packed randomly into a column in a shaped form,
allowing fluid to flow through the interstitial voids. Key to the effectiveness of packed columns are the flowrelated properties of mass transfer, fluid distribution and dispersion, and back pressure, which in turn depend
upon packing geometry. Until now, no alternative was found to overcome this limitation and have optimal
ordered packing arrangements at the micron scale. 3D-Printing (or additive manufacturing) brings a wide range
of benefits that traditional methods of manufacturing or prototyping simply cannot. With this approach, complex
ordered geometries, that are not possible by conventional extrusion, can be designed and printed for a porous
media, being the equipment resolution the only limiting step to overcome.
The effect of parameters like compression force, particle sieving, binder nature, binder/adsorbent ratio were
firstly studied using conventional shaping techniques, as a basis for the consequent development of 3D-printed
formulations. The structured samples are then characterized and adsorption equilibria studies are performed on
them to evaluate their performance as media for gas adsorption separation processes. A volumetric/manometric
adsorption unit built in-house was used for this purpose. Relevant experimental data is obtained, which allows to
conclude that 3D-printed media can be an alternative porous media for application in gas adsorption processes.

Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping is investigated, and correlated with the morphology and the optical properties of the self-assembled silver nanoparticles incorporated in the cells’ back reflector.

Silver (Ag) and tin (Sn) nanoparticles (NPs) were deposited by thermal evaporation onto heated glass substrates with a good control of size, shape and surface coverage. This process has the advantage of allowing the fabrication of thin-film solar cells with incorporated NPs without vacuum break, since it does not require chemical processes or post-deposition annealing. The X-ray diffraction, TEM and SEM properties are correlated with optical measurements and amorphous silicon hydrogenated (a-Si:H) films deposited on top of both types of NPs show enhanced absorbance in the near-infrared. The results are interpreted with electromagnetic modelling performed with Mie theory. A broad emission in the near-infrared region is considerably increased after covering the Ag nanoparticles with an a-Si:H layer. Such effect may be of interest for possible down-conversion mechanisms in novel photovoltaic devices.

Plasmonic light trapping in thin film silicon solar cells is a promising route to achieve high efficiency with reduced volumes of semiconductor material. In this paper, we study the enhancement in the opto-electronic performance of thin a-Si:H solar cells due to the light scattering effects of plasmonic back reflectors (PBRs), composed of self-assembled silver nanoparticles (NPs), incorporated on the cells’ rear contact. The optical properties of the PBRs are investigated according to the morphology of the NPs, which can be tuned by the fabrication parameters. By analyzing sets of solar cells built on distinct PBRs we show that the photocurrent enhancement achieved in the a-Si:H light trapping window (600 – 800 nm) stays in linear relation with the PBRs diffuse reflection. The best-performing PBRs allow a pronounced broadband photocurrent enhancement in the cells which is attributed not only to the plasmon-assisted light scattering from the NPs but also to the front surface texture originated from the conformal growth of the cell material over the particles. As a result, remarkably high values of Jsc and Voc are achieved in comparison to those previously reported in the literature for the same type of devices.