A Density Staggered Cantilever for Micron Length Gravity Probing

A density staggered cantilever was developed to measure the micron length gravity between itself and an optically levitated microsphere in high vacuum. The cantilever, has two main density contrasted materials gold(19.3g/cm3) and silicon(2.33g/cm3), where each of the material is finger-shaped and stagger placed next to each other, constitute an integral finger array on the device layer of SOI wafer. The scallop of the DRIE defined fingers was optimized to be less than 50nm to reduce the surface variation between the cantilever and levitated microsphere. The end of each fingers were covered with 2-10um silicon and gold to shield the undesired charged particles. The back side of SOI wafer were defined with DRIE to release the cantilever. The Cantilever will be placed microns away from the microsphere and mechanically move back and forth to interact with the microsphere. This paper introduces the design, manufacturing of the density staggered cantilever for micron length gravity.