REGULAR FIBER COMPOSITES

Smart Material manufactures 1-3 composites using piezo ceramic fibers as the active rods. The fibers are infiltrated with epoxy and the cube shaped blocks are then diced perpendicular to the fibers, a patented method known as Arrange and Fill. Here the fibers are laid out at a fixed spacing, which gives a regular distribution.

Fiber composites are a cost effective alternative to the Dice and Fill method. Arranging 800 µm ceramic fibers at a constant pitch gives fill factors from roughly 15 per cent up to a maximum of 48 per cent.

This material was designed specifically for sonar and other underwater ultrasound work. A modified vacuum deposition process produces a low impedance copper flash tin layer, typically 2.5 µm thick, which is durable and solders well.

• Frequencies from 80 kHz to 1 MHz
• PZT Navy type II
• Fill factors from 15 to 48 per cent
• Maximum size 10 cm by 10 cm, larger on request
• A choice of epoxy and polyurethane interstitial materials
• Operating temperatures up to 135 ℃
• Gold, copper tin or silver electrodes

Product specifications and options

Typical ultrasound applications

• Sonar array transducers
• Sonar single element transducers
• General underwater ultrasound
• Air ultrasound transducers

Because of the Arrange and Fill method, the raw material arrives as blocks up to 10 cm long with the lateral dimensions of the target element. As well as slicing elements to the resonance frequency you need, the block can be machined into other shapes, including precise concave and convex contours for broadband ultrasound receivers.

The method scales easily to volume, which keeps lead times short. That is a significant advantage over Dice and Fill, particularly at low frequencies. A range of standard epoxy and polyurethane fillers allows operating temperatures between 95 and 135 ℃.