Geometrically predictable micro fabricated continuum robot

Abstract

Compared to the micro continuum robots that use traditional manufacturing technology, the micro fabricated continuum robots are different in terms of the application of smart materials, additive manufacturing process, and physical field control. However, the existing geometrical prediction models of the micro continuum robots still follow the model frameworks designed for their larger counterparts, which is inconsistent with the real geometrical transformation principle of micro fabricated continuum robots. In this paper, we present a universal geometrical prediction method for the geometry transformation of the micro fabricated continuum robots based on their material properties and the displacement of the stress points. By discretizing of the micro fabricated continuum structure and applying force constraints between adjacent points to simulate material properties, formulations and simulations are demonstrated to prove the feasibility and effectiveness of the proposed method. Three micro fabricated continuum robots driven through different external field forces are investigated to show two superiorities: the geometrical deformation of a micro fabricated continuum robot under external disturbances can be predicted, and a targeted geometry can be shaped by predicting the sequence and directions of external forces. This pioneer research has contributed to promote understanding and operation of micro fabricated continuum robots and their deformation both from theoretical aspect and real experimental operations.

Figures (6)

• Figure 1: The methodology of the proposed geometrical prediction. (A): The proposed geometrical prediction method; (B): The sketch of deformation and discretization of a micro fabricated continuum robot; (C): Mechanical analysis between adjacent points.
• Figure 2: Simulated shapes of micro fabricated continuum robots calculated by the proposed method. (A): The geometrical transformation process of a micro fabricated continuum robot predicted by the proposed method; (B): Shape of micro fabricated continuum robots with different elastic coefficient of the spring; (C): The effect of different equivalent spring original length on the geometry of a micro fabricated continuum robot; (D): The effect of different thresholds of the tensile deformation amplitude of the equivalent spring on the geometry of a micro fabricated continuum robot. The unit is $\mu$m in this coordinate system.
• Figure 3: Micro fabricated continuum robot with wave like geometrical deformation. (A) An conceptual diagram of geometrical deformation of a micro fabricated continuum robot under external disturbances; (B) A predicting result of geometrical deformation of a micro fabricated continuum robot when stress points distribute at large distance; (C) A predicting result of geometrical deformation of a micro fabricated continuum robot when stress points in close distance. The unit is $\mu$m in this coordinate system.
• Figure 4: Experiment results of micro fabricated continuum robot's geometrical deformation. (A): A experimental result of geometrical deformation of a micro fabricated continuum robot when stress points distribute at large distance; (B): A experimental result of geometrical deformation of a micro fabricated continuum robot when stress points in close distance. The white bar is 200$\mu$m.
• Figure 5: Deform micro fabricated continuum robots into designed letters PKU. (A)The concept of geometric deformation process from an initial form of a straight line into the shape of the letter PKU; (B)The predicted geometric deformation into letter PKU by our method