Using microscopic variations on the sawtooth gear in a winch, Brownian ratchets convert the random jitter of particles into useful work, such as sorting viruses by size or removing contaminants from water.

• 运用绞盘中锯齿的微观变形，布朗棘轮可以把粒子的随机乱动转变成有用的行为，如筛选不同大小的病毒，或是将水中的污染物去除。