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Active Personnel:

  • Giuseppe Del Giudice
  • Dr. Jin-Hui Shen - Department of Ophthalmology
  • Dr. Karen Joos - Department of Ophthalmology
  • Dr. Nabil Simaan




This NSF funded project is designed to demonstrate a new class of continuum robots capable of multi-scale manipulation; that is, the ability to achieve large motion with millimetric precision and to achieve small motion with micrometer-scale precision. In contrast, existing robots are mainly designed to function properly only at a single functional length scale. In the past, there are works done on manipulators that are able to offer this kind of dual scale of motion, Egeland 1987 IEEE TRO or Comparetti 2012 IMechE JEM for example,  but the majority of them rely on serial staking of macro-manipulators, most likely on the serial structure architecture, with a micro-manipulator, typically built as a parallel robot, attached to the end effector position. In addition, There are also other manipulators that use to vary the structural equilibrium pose to achieve micro movement, Portman 2001 JMTM for example, but all these concepts share the same problem, it is a bit of a challenge to implement them in a surgical application due to space consideration. There are also manipulators that are size compatible with the surgical application, Webster IEEE/RSI IROS 2006 for example, but on the other hand are not able to provide multiscale motion independently.

The aim of this project is to extend the capabilities of a standard continuum robot in term of micro-scale motion and targeting possible application of this fine movement. The envisioned class of robots will provide micro-precision while traversing macroscale sinuous pathways to access the operational site. Potential benefits include precise tissue reconstruction and complete surgical eradication of tumors. Such robots will also enable new abilities for micro-manufacturing, leading to greatly improved quality-control inspection methods for micro-fluidic and microelectromechanical devices mass-manufactured on large substrates.


CREM Concept

The augmentation of the macro-scale workspace of multi backbones robot with micron-scale motion capabilities is achieved using this new concept of continuum robot with equilibrium modulation or in short CREM. 

This robot is still able to achieve the large scale of motion using the tubular secondary backbones. Those are rigidly attached to the top red end disk and by direct actuation, pushing and pulling on them, we can change the continuum robot configuration. Now in addition to that, we have wires (marked in red in the picture), inside the structure that can slide in and out of the tubular backbones.

While these wires are sliding, we are able to modulate the equilibrium shape. This is obtained through redistribution of cross-sectional stiffness along the length of the snake segment. 



Micromotion Tracking

Part of the efforts for this project is aimed to be able to track the end-effector position and orientation on a macro and micro scale. The micromotion tracking it is used for loop-closed control purpose and visual servoing. Due to the lack of commercial tracker able to track the fine motion generate on the micromotion mode, a new visual tracking process has been designed, developed and tested. The results of such tracking process can be seen on this video generated as a multimedia extension for the publication authored by Giuseppe Del Giudice IROS 2017.



Poster of the planned research was presented at the VISE 6th Annual Surgery, Intervention and Engineering Symposium, Nashville,TN, USA, Dec 2017. A copy of the PDF poster is available here.








  • Del Giudice, G., Wang, L., Shen, J., Joose, K. and Simaan, N., "Continuum Robot for Multi-Scale Motion: Micro-Scale Motion Through Equilibrium Modulation", IEEE/RSJ International Conference on Intelligent Robots and System (IROS'), Vancouver, Canada, 2017 (accepted).