ABSTRACT
However, the artificial kidney dialysis has several disadvantages, such as line wastage from blood during dialysis, which takes about 2-4 hours time to clear. For this, the patient has to visit the hospital two to three times in a week. This led researchers and inventors to develop implantable artificial kidney [15], which was convenient for the patients. Optical trapping was first discovered by Ashkin [16].It emerged as a powerful tool and had broad applications in biology, physics, engineering, and medicine [17]. The ability of optical trapping and manipulating viruses, living cells, and bacteria by laser radiation pressure without destroying the organelles [18] being treated has been demonstrated in some experiments [19, 20].The application of nanotechnology to medicine was shown experimentally by Lee et al. [21, 22] through the single red blood cell (RBC) deformability test performed by using optical trapping plastic in a microfluidic chip and through lab-on-a-chip for the transportation of RBCs in a capillary network to circulate oxygen and carbon dioxide throughout the human body [23]. Suwanpayak et al. [24] reported that optical trapping can be used to manipulate molecules in a liquid core waveguide and can be applied for drug delivery, wherein a PANDA ring resonator is used to form, transmit, and receive the microscopic volumes (of drugs) by controlling the ring parameters. The microscopic volume can be trapped and moved (transported) dynamically within the wavelength router or network. Recently, a promising technique of microscopic volume trapping and transportation within an add/drop multiplexer have been reported in theory [25] and experiment [26]. Here the transporter is known as an optical tweezer. The optical tweezer generation technique is used as a powerful tool to manipulate micrometer-sized particles. To date, useful static tweezers have been well recognized and realized. Moreover, the use of dynamic tweezers has now also been realized in practical work [27-29]. Schulz et al. [30] have shown that it is possible to transfer trapped atoms between two optical potentials. Optical tweezers use forces exerted by intensity gradients in strongly focused beams of light to trap and move nanoscopic volumes of matter. During the movement, another combination of forces is induced between photons due to their interactions caused by photon scattering effects. The field intensity can also be adjusted and tuned to the desired gradient field and scattering force so that the suitable trapping force can be formed. Thus, by configuring the
appropriated force for the transmitter/receiver part, nanoscopic particles can be transported over a long distance. In this chapter, the methods for generating the dynamic optical tweezers/vortices using a dark soliton, a bright soliton and a Gaussian pulse propagating within an add/drop optical multiplexer with two nanoring resonators (PANDA ring resonator) will be discussed. The dynamic behavior of soliton and Gaussian pulses is well described by some authors [22]. By using the proposed system, the blood waste and unwanted substances can be trapped and transported (filtered) from the artificial human kidney. The required trapping tool sizes can be generated and formed for the specific blood waste molecules, and clean blood can be obtained and sent to its destination via the through port. However, several sensors are required for environmental and blood quality control, which is the topic for future research. 10.2 Theoretical BackgroundTrapping forces are exerted by the intensity gradients in the strongly focused beams of light, which can be used to trap and move microscopic volumes of matter, in which the optical forces are customarily defined by the relationship [21].mQn PF
c (10.1) Here Q is a dimensionless efficiency, nm the index of refraction of the suspending medium, c the speed of light, and P the incident laser power for the specimen. Q represents the fraction of power utilized to exert force. For an incident plane wave on a perfectly absorbing particle, Q is equal to 1. To achieve stable trapping, the radiation pressure must create a stable, three-dimensional equilibrium. Because biological specimens are usually contained in aqueous medium, the dependence of F on nm can rarely be exploited to achieve higher trapping forces. Increasing the laser power is possible, but only over a limited range due to the possibility of optical damage.
