Fibers with a variety of cross sections can be made using VSSP (Figs. 1
and 2). Fibers with a variable diameter, such as that shown in Fig. 2, are of
interest for composite reinforcement. These were developed with Yuntian
Zhu of Los Alamos National Lab, Los Alamos, N.M., and can potentially
increase pullout stress by mechanically locking to the matrix.6,7
Current work at ACI—in conjunction with the University of Notre
Dame (South Bend, Ind.) and Zimmer Inc.—on variable-diameter
fibers focuses on reinforcement of bone cement using variablediameter
hydroxyapatite fibers. Variable-diameter ceramics have
potential as the reinforcement phase in ceramic- and metalmatrix
composites.
Of all the ceramic fibers developed by ACI to date, PZT fibers
have been the most successful, commercially. The breakout use
of ACI’s PZT fibers is in piezoelectric fiber composites. Head
Sport AG (Kennelbach, Austria) has built its entire Intelligence
product line based on ACI’s piezoelectric-fiber composites. The
Intelligence line of smart tennis rackets (Fig. 3) has been
particularly successful.