From Macroscopic to Microscopic: Experimental and Computational Methods to Investigate Bio-tribology

Tribology is an important factor (among other factors) during biological interactions of devices and tissues. The paper discusses how new computational and experimental methods can be used to understand and improve the design and development of medical devices at macro and micro scales to sustain life beyond 50 years. We have used pre-clinical experiments and computational methods to understand interactions between orthopaedic implants at the macro scale. The computational model has been validated with experiments. Now this computational model can predict damage in implants for different patients. One such application was successfully tried and tested in collaboration with University National Autonomous Mexico. This methodology can be used in future to design patient specific, affordable (using 3D printing) and robust implants which will be useful for developing countries like Vietnam, India and Mexico. Improvement of catheter designs is important to reduce damage to the internal tissues while being used for cardiovascular problems. We are developing new experimental techniques (in micro scale) that can be used to understand the interaction of cells with the catheter material. These will help reduce the hospital costs incurred during longer stay of the patients admitted for cardiovascular related problems

Impact of Tuned Mass Dampers and Electromagnetic Tuned Mass Dampers on Geometrically Nonlinear Vibrations Reduction of Planar Cable Robots

Vibration is one of the problems that limits the applications of cable driven parallel robots (CDPR). The problem is bigger in CDPR with planar configuration due to the presence of out-of-plane vibrations, which have a larger amplitude and settling time. Some authors have proposed solutions such as the increase in tension of the wires, increase in the end effector mass, or the use of active dampers. In this research, we investigated the performance of tuned mass dampers (TMD) and electromagnetic tuned mass dampers (ETMD) which are integrated in the end effector of a CDPR in a planar configuration with eight wires. The essential idea is to reduce the settling time of the end effector through free vibrations without the use of external energy. This research followed an analytical and experimental methodology with the following steps. Three mathematical models were formulated and analysed using numerical simulations. Then, a test bench to validate the analytical results was designed and built. The effectiveness of the dampers was evaluated by comparing the settling times of the following three cases: without damper, with TMD, and with ETMD. During the investigation, it was observed that the use of AMS can reduce the settling time using the appropriate parameters. The effectiveness of AEMS is highly dependent on frictions and can be effective in some scenarios. Reductions in settling time from marginal values to 95% can be obtained. This research implies a viable solution for the out-of-plane vibrations of planar CDPR

Application of comparative design study in the development of preservation encasements for historical documents

The preservation of historical documents is a task that requires a multidisciplinary team. Mechanical engineering can make valuable contributions. Historical documents made of paper have unique characteristics that must be considered for their preservation and exhibition. Specially designed encasements have emerged as a solution to meet these requirements. In the present research, a comparative design study was carried out. The study comprises identifying the main functions of the encasements. Subsequently, it is analyzed how the capsules that appear in the literature have solved these functions. With the information obtained, three new encasements were designed for historical documents in Mexico. From the results and design experiences, some insights and design principles were obtained; these can be universally applied