Make a Mobius strip out of a ribbon of mild steel and magnetise it.

用一根软钢条做成麦比乌斯带，将其磁化。

Simply magnetise a spot or, more usefully, many spots, and the spots' status can be detected by measuring the changes they induce in the electrical resistance of a tiny sensor placed nearby.

其方法很简单, 只要对一个点或多个点进行磁化以发挥更大的功效, 然后在其附近放置一个微小的传感器就能检测到它们在电阻下的变化从而得知各点的状态.