A microfiber-based Mach-Zehnder interferometer (MZI) for measurement of absolute strain is proposed and demonstrated experimentally. The diameter of the microfiber is optimized to induce the negative thermo-optic effect in the microfiber MZI and the temperature sensitivity of the microfiber MZI is successfully suppressed. When the diameter of the microfiber is ~5 μm, the temperature sensitivity of the microfiber-MZI is dramatically mitigated. We apply the proposed microfiber MZI for absolute strain measurement and its strain sensitivity is measured to be ~7.13×10-2 nm/ μЄ.
Recently, a bacteria-based drug delivery system has been proposed to achieve effective and localized drug delivery. Researchers have shown that flagellated bacteria have a chemotactic property to tumor cells, and they can be used as an energy source for active drug delivery. Our previous results have reported that a circular droplet made by a biodegradable polymer can be used in this bacteria-based, robotic drug delivery. In this paper, using laminated cubic structures made of several layers of biodegradable polymers for bacteria-based microrobot is proposed. The structures are made by laminating polymer layers and then, micromachining them using a deep X-ray synchrotron radiation into 40 μm x 40 μm x 40 μm cubes. The cubic structure is more beneficial in attaching bacteria in only selective surface directions than a circular structure, and in controlling the volume of drugs to be encapsulated with the outer polymer layer.
Micro-tapered long-period fiber gratings (MT-LPFGs) written in tapered fibers with different diameters of 125, 100, 75,
and 50 μm are fabricated and their transmission characteristics with variations in strain and temperature are investigated.
Since the variation of the refractive index with the applied strain change is inversely proportional to the cross section
area of the MT-LPFGs, the strain sensitivity of the MT-LPFGs is further improved. The temperature sensitivity is also
enhanced by reducing the diameter of the tapered fiber. The experimental results are very useful for discrimination of
strain and temperature sensitivities.