The modification in the third-order nonlinear optical behavior exhibited by a titanium dioxide thin solid film with embedded Gold-Platinum nanoparticles was induced by nanosecond optical pulses. A Nd:YAG laser system was employed for the experiments explored by a vectorial two-wave mixing method with the sample in rotation. The nanostructures were prepared by a sol-gel technique. Transmission Electron Microscopy studies and ultraviolet-optical spectroscopy measurements were undertaken. The evolution of the optical transmittance exhibited by the sample in rotation controlled by a servomechanism was observed. Potential applications for developing mechanooptical functions based on third-order optical nonlinearities were contemplated.

This work addresses the design, analysis, and validation of a transtibial custom prosthesis. The methodology consists of the usage of videometry to analyze angular relationships between joints, moments, and reaction forces in the human gait cycle. The customized geometric model of the proposed prosthesis was defined by considering healthy feet for the initial design. The prosthesis model was developed by considering the Flex-Foot^® Variflex^® architecture on a design basis. By means of the analytical method, the size and material of the final model were calculated. The behavior of the prosthesis was evaluated analytically by a curved elements analysis and the Castigliano theorem, and numerically by the Finite Element Method (FEM). The outcome shows the differences between the analytical and numerical methods for the final prosthesis design, with an error rate no greater than 6.5%.

Piezoelectric materials are fundamental elements in modern science and technology due to their unique ability to convert mechanical and electrical energy bidirectionally. They are widely employed in sensors, actuators, and energy-harvesting systems. In this work, we investigate the behavior of commercial lead zirconate titanate (PZT) sensors under frequency-mode excitation using a combined approach of impedance spectroscopy and optical interferometry. The impedance spectra reveal distinct resonance–antiresonance features that strongly depend on geometry, while interferometric measurements capture dynamic strain fields through fringe displacement analysis. The strongest deformation occurs near the first kilohertz resonance, directly correlated with the impedance phase, enabling the extraction of an effective piezoelectric constant (~40 pC/N). Moving beyond the linear regime, laser-induced excitation demonstrates optically driven activation of piezoelectric modes, with a frequency-dependent response and nonlinear scaling with optical power, characteristic of coupled pyroelectric–piezoelectric effects. These findings introduce a frequency-mode approach that combines impedance spectroscopy and optical interferometry to simultaneously probe electrical and mechanical responses in a single setup, enabling non-contact, frequency-selective sensing without surface modification or complex optical alignment. Although focused on macroscale ceramic PZTs, the non-contact measurement and activation strategies presented here offer scalable tools for informing the design and analysis of piezoelectric behavior in micro- and nanoscale systems. Such frequency-resolved, optical-access approaches are particularly valuable in the development of next-generation nanosensors, MEMS/NEMS devices, and optoelectronic interfaces where direct electrical probing is challenging or invasive.

This work focuses on the analytical and numerical exploration of the contrast in the dynamic behavior of C60 fullerenes and nanodiamonds suspended in a liquid ethanol solution. A comprehensive study reveals different sedimentation times related to the structure of the samples; demonstrating that it is possible to achieve a selective structural separation of carbon nanoparticles of the same size. One of the main goals was to find numerical solutions regarding the dynamic properties exhibited by nanodiamonds. However, due to the random behavior of nanoparticles, it was necessary to generate a set of random measurements to generate the parameters required for the study of this type of systems. The maximum precipitation values ​​were estimated for a set of nanoparticles encapsulated in liposomes. The results showed that there is a direct influence of internal forces on the sedimentation process, showing that the gravitational force is not strong enough to cause the suspended nanoparticles to constantly settle. This limit was determined by taking the external force of gravity and the internal forces related to the buoyancy force and friction. Finally, in order to strengthen our research, a comparative study of the Brownian behavior of a nanofluid composed of nanodiamonds and C60 fullerenes under light illumination is evaluated, allowing us to obtain a general selective method to separate two types of nanoparticles of different geometry and size, but with different densities. This research can be a base to estimate the behavior associated with the transport of nanoparticles, generating a simple and effective method for the selective separation of nanoparticles in a liquid medium.