[Application and electric insulation of strain gauges used on fresh bone. Preliminary study]

This report describes the optimal use of strain gauges placed on fresh wet bones. Two principal stages in gauge installation were studied: surface preparation and gauge insulation. Different surface preparation procedures were tested on bovine bone specimens loaded in traction. The preparation efficiency was evaluated by comparing strains measured from gauges and from an extensometer with sharp edges. Results show the necessity of sufficient rubbing: a minimum of 5 rubbing cycles with n. 320 emery paper. Scanning electron microscopy was used to examine the effect of the preparation procedures. Different coatings were also tested with special attention given to the influence of these coatings on the measured strains. An optimal polyurethane coating is proposed.