Piezoresistive sensors for force mapping of hip-prostheses

The success of artificial prosthetic replacements depends on the fixation of the artificial prosthetic component after being implanted in the thighbone. The materials for fixation are subject to mechanical stresses, which originate permanent deformations, incipient cracks and even fatigue fractures. This work shows the possibility of monitoring the mechanical stress over time in prosthesis. In this way, highly sensitive silicon thin-film piezoresistive sensors were developed attached to prosthesis and their results compared with commercial strain gauge sensors. Mechanical stress-strain experiments were performed in compressive mode, during 10,000 cycles. Experimental data was acquired at mechanical vibration frequencies of 0.5 Hz, 1 Hz and 5 Hz, and sent to a computer by means of a wireless link. The results show that there is a decrease in sensitivity of the thin-film silicon piezoresistive sensors when they are attached to the prosthesis, but this decrease does not compromise its monitoring performance. The sensitivity, compared to that of commercial strain gauges, is much larger due to their higher gauge factors (-23.5), when compared to the GFs of commercial sensors (2).

Corruptos Submarinos: Portugal Envergonhado

Recordar é viver. O famoso caso de corrupção internacional ligado à compra e venda de submarinos pelo Estado português – e que ainda não está resolvido na sua totalidade, nomeadamente por cá – constitui um facto repugnante da história contemporânea da anti-corrupção, e da ética, também lusa que envergonha em profundidade Portugal a nível nacional, mas sobretudo internacional. E envergonha, quer o poder legislativo, quer o poder judicial, quer o poder executivo. Em Portugal, mas também na Alemanha, pois nem toda a informação criminal chegou às autoridades portuguesas como foi noticiado pelos próprios procuradores. § Remember is living. The famous case of international corruption linked to the purchase and sale of submarines by the Portuguese State - and that is still not resolved in its entirety, especially around here - is a disgusting fact of contemporary history of anti-corruption and ethics, also Portuguese who shames Portugal in depth at national level, but above all international. And shame either the legislature or the judiciary or the executive. In Portugal, but also in Germany, as not all criminal information came from the Portuguese authorities was as reported by their own attorneys.