Experimental Research And Design Of The Spherical And Optical Film System Detecting For Micro-nano Newton Force

The detection of micro-nano Newton force in many engineering applications has been more andmore significant. With the development of micro-nano technology and biomedical technology, thesefields such as biology and medicine, cytology, molecular chemistry, genetics (DNA), environmentdetection (bacterium), the food industry (microorganisms) and Nano manufacturing would bepromoted by the detection of micro-nano Newton force. At present, the detection technology of themicro-nano Newton force applied in all fields remains in an early stage of experimentation andinvestigation. Developing a system detecting for the micro-nano Newton force which is easy to usewith low cost, and simple to manufacture would be very important.The spherical and optical film system detecting for the micro-nano Newton force was designedin this paper. There are two sub-systems in this detection system. The nano-Newton level force wasdetected in the first sub-system using a water-soluble spherical film as sensitive element. In addition,the micro-Newton level force was sensed in the second sub-system using a natural emulsion sphericalfilm as sensitive element. In the sub-system sensing for the nano-Newton force, the industrial CCDwas applied to acquire the image of light interference fringe on the surface of water-soluble sphericalfilm. The original image was acquired by the industrial CCD before the nano-Newton level force wasapplied on the water-soluble spherical film. After the nano-Newton level force was applied on thewater-soluble spherical film, the interference fringe would be changed; then the changed image wasobtained. Thus, the nano-Newton level force was detected by comparing the difference between theoriginal image and the changed image. In sub-system detecting for micro-Newton level force, thedetecting principle was mainly based on the laser reflection effect. The position sensitive detector(PSD) was used to detect the change of laser spot position reflected from the surface of naturalemulsion spherical film. According to the change, the micro-Newton level force was detected.The relation equation of the nano-Newton force, the diameter of water-soluble spherical film andthe width variation of interference fringe was built by using the method of orthogonal experiment inthis paper. Meanwhile, the relation equation of the micro-Newton force, the diameter and thickness ofnatural emulsion spherical film and the reflection range of laser was built by the same method.Furthermore, the detecting system mathematical models of different ranges were constructed and thedetected error was analyzed. The detecting requirements were met in the error ranges of-5.7%~6.2%and-2.5%~5.3%. The validity and correctness of the optical spherical film system detecting for the micro-nano Newton force were verified. Finally, we expected to provide a relevant principle andreference for the research field of detecting for the micro-nano Newton force.