Table 7.3. Directions For Preparing Simulated Brain Material
For 915 and 2450 MHz (Guy, 1971a; Chou et al., 1984)
- Weigh all ingredients and determine percentages by weight.
- Mix ingredients except TX-150 in 14-20°C water with a 4-in. shear stirrer rotating at 450 rpm on a variable-speed drill press until all polyethylene powder is wet. Add one drop of household liquid detergent to help wet the polyethylene powder.
- Add TX-150 and increase drill press speed to 1200 rpm.
- Mix for about 45-120 s. When the mixture becomes thick, slow the drill press to about 800 rpm to avoid generating air bubbles. Since the setting time of TX-150 varies with factory batch, proper water temperature and mixing time must be determined by experience. If stirred too long, the mixture may be filled with air; if not stirred enough, the polyethylene powder will float. The larger amount of polyethylene powder in this mixture makes it more difficult to determine the correct stirring time.
- When the mixture looks soupy, pour it into a plastic bag and let it set; then force it into the mold.