Optimized fabrication of micropipette using laser micromachining process and application in functional electrical stimulation of muscle tissue

A thin tapered glass micropipette has been widely applied in biomedical application. During the micromachining process of tapered micropipette by P-2000 laser-based micropipette puller, four process parameters affect the shape of the micropipette, and they are Heat, Velocity, Delay and Pull, respectively. Because of the interaction between any two of these factors, it is difficult to find the optimal parameters to meet the requirement of micropipette tip shape. A special micropipette shape for the application of functional electrical simulation is fabricated and optimized by the orthogonal experiments. The micropipette shape is with a tip diameter of 10 μm, the change value of the tip diameter located at the length of 100 μm as small as than 11.5 μm and total length of 6–12 mm. The experimental results show that the optimum matching ones in the given values of the discrete parameters are with the Heat setting of 700, the Velocity setting of 45, the Delay setting of 145 and the Pull setting of 225. The results and analysis presented in the manuscript are based on the use and settings of CO2 laser-based micropipette puller (P-2000, Sutter Instrument) and no physical equivalence could be defined for the various settings except the Delay parameter. Then its application for functional electrical stimulation of muscle tissue is introduced and the corresponding experiments are performed.

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► The special shape of the micropipette electrode can be optimized by the orthogonal experiments.
► The quartz micropipette which is fabricated and optimized by P-2000 laser-based micropipette puller can be used in FES.
► The change of the tip diameter of 10 μm at the length of 100 μm is 1.34 μm.
► The EMG signal is recorded by the fabricated micropipette and setup platform.