This paper proposes a novel capsule robot (CR) with spring-connected legs for potential usage in the gastrointestinal (GI) tract. The proposed CR has a set of six legs and is actuated by a micromotor through internal mechanisms. Every two adjacent legs are connected by a spring. The leg opening-folding movement, together with the spring stretching-contraction motion, may be employed to distend the GI tract, carry out drug delivery or perform biopsy. The relationship between the driving force required by the spring set and the spring length was carefully calculated and simulated. This relationship was also measured by an NI data acquisition system. The calculated and measured data showed good accordance with each other. In addition, the driving force from the micromotor was calculated. Both the calculations and the CR experiments demonstrated that the internal motor could provide sufficient force on the springs.

Based on a previous study of a novel capsule robot (CR) with spring-connected legs that could collect intestinal juice for biopsy, in this research, an experiment system is designed, and two experiments are carried out. One of the experiments measures the torque and cutting force of this CR, and the other experiment tests and evaluates the biopsy function of this CR. In the measuring experiment, we analyze how the magnetic torque exerted on this CR changes. In the experiment with a biopsy, we decompose the biopsy actions and select the most effective biopsy action. The result of the experiments shows that this CR can collect and store biopsy samples ideally, and the most effective biopsy action is the rotation with legs extended.