Frequency selectable induction heating targets

This paper examines a scheme for developing frequency selectable induction heating targets for stimulating temperature sensitive polymer actuators. "Frequency selectable" implies that each target has a frequency at which it heats preferentially compared to other remaining targets. Single-turn conductors whose critical dimensions are small compared to their associated skin depth (over the frequency range of interest) are examined. One way to achieve selectivity with frequency is by designing each target to have the same self-inductance, while forcing the resistance of each target to differ from the previous one by a specified factor, /spl alpha/. In this way, a target driven at its R/L break-point frequency, will heat by at least a factor of (/spl alpha//sup 2/ + 1)/(2/spl alpha/) more than the remaining targets.