Surface topography and, in particular, roughness and form, plays an important role in determining the functional performance of engineering parts. The measurement and understanding of surface topography is rapidly attracting the attention of the physicist, the biologist and the chemist as well as the engineer. Optics in general played an important role in measurement and, with the advent of opto-mechatronics, it is once again at the forefront of measurement. In this paper, the principles and performance of a confocal microscope, together with the measurement system, are described. Suitable fixtures are developed and integrated with the computer system for generating three-dimensional surface and form data. Software for data acquisition, analysis of various parameters including new parameters and visualization of surface geometrical features has been developed. Both the intensity and the auto-focus methods are used to measure two-dimensional surface roughness by use of the system and results are presented. The measurement and characterization of three-dimensional surface topography and form error will be presented in part II of this paper.

The necessity of the soft gripping devices is increasing day-by-day in medical robotics especially when safe, gentle motions and soft touch are necessary. In this paper, a novel asymmetric bellow flexible pneumatic actuator (AFPA) has been designed and fabricated to construct a miniaturised soft gripper that could be used to grip small objects. The model of AFPA is designed using solid works and its bending motion is simulated in Abaqus software for optimisation and compared with experimental results. The actuator is fabricated using compression molding process that includes micromachining of the molds. Experiments conducted show the bending characteristics of the actuator at different pressures. The actuator shows excellent bending performance and the eccentricity in its design supports increased bending or curling motion up to a certain extent compared to normal bellows without eccentricity. The effects of profile shape and eccentricity on the actuator performance are analysed and the results are presented.

In part I, considering the autofocus and intensity methods of measurement, the principles and performance of a confocal microscope were discussed. In this part, the details of the experiments, conducted to measure and assess micro and macro surface irregularities of various machined planar and cylindrical surfaces, using a confocal scanning optical microscope (CSOM) are described. The three-dimensional surface topographies of various machined planar surfaces and also the form errors, like roundness and cylindricity, are measured and analysed. The significance of the set of new parameters, proposed for characterizing three-dimensional surface roughness and roundness measurements, is indicated. The effect of filtering on the variation in values of three-dimensional surface-topography parameters is studied. The performance of the CSOM is compared with those of conventional stylus and interferometric methods. The system is shown to have a great number of advantages in terms of three-dimensional surface mapping of planar and cylindrical surfaces and recognition of details and analysis for characterization of surfaces.

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