The magic happened when they added magnetic particles.

当他们加入磁性粒子时，奇迹发生了。

Or, if I say that MRI machines use magnetism to rotate magnetic particles in your body, you've seen it done.

或者，如果我说 MRI 机器使用磁力来旋转您体内的磁性粒子， 您已经看到了。

To create a millimeter-scale robot capable of feats of flexibility, the researchers embedded magnetic particles of the element neodymium in pliable material.

为制造出具有灵活性的毫米级机器人，研究人员将钕元素的磁性颗粒嵌入柔韧材料中。

That will involve hands-on checking of practically every square inch of steel on the bridge, and probably non-destructive tests that can identify defects like using x-rays, magnetic particles or dyes that make cracks more apparent.

这将涉及对桥梁上几乎每一平方英寸的钢材进行实际检查，并可能进行非破坏性测试，以识别缺陷，例如使用 X 射线、磁性粒子或染料来使裂缝更加明显。