Session: FSI-05-01 International Symposium on Emerging Technologies

Paper Number: 61929

Start Time: Tuesday, July 13, 2021, 08:00 PM

61929 - Evaluation of Water Flow on Interfacial Strength in PSA Film Delamination 

In cataract surgery, an artificial lens is inserted in place of a lens, which is a tissue in an eye, after the lens got clouded due to cataract. In the surgery, there is a process that the lens and a capsule, which is a tissue like a membrane and is covering and attached to the lens, are delaminated. The technique called irrigation dynamic pressure-assisted hydrodissection (iH) can promote the delamination more easily and with less incidence of complications in the surgery due to a load on the capsule than the conventional method called manual hydrodissection (mH). In mH, a syringe filled with water is inserted between the two tissues, and the water in the syringe is pushed in to delaminate them. In iH, water goes between the tissues by water column pressure, and at the same time, water is suctioned through outlet so that water flow is generated. Therefore, it is considered that the water inflow and aspiration influence the delamination of the capsule, but the mechanism of this effect has not been well understood. Therefore, the purpose of this study is to clarify the mechanism of the effect of water inflow and aspiration on a thin film delamination phenomenon so that more effective ways to use the inflow and aspiration will be explored and the incidence of complications in cataract surgery will be reduced in the future.

Focusing on dynamic pressure as an effect of water flow, it was investigated how much dynamic pressure works on the delamination of thin film. A series of irrigation and delamination experiments were conducted using a modified blister test newly developed for this research. It is used to measure the energy release rate of pressure sensitive adhesive tape attached to a substrate. In the experiments, water flows into a blister, which is a swelled membrane, by water column pressure through a channel and water can be suctioned out of the blister through another channel by using a suction pump.

To observe the contribution of water flow to a delamination of a thin film, the similar situation was simulated by FEM. A method called CEL, where fluid is modeled by Eulerian mesh, solid is modeled by Lagrangian mesh and an interaction of them can be simulated, and an interface bonding force model were used to reproduce the delamination. The delamination of the thin film by water flow was reproduced when velocity of water flow was higher than the value obtained in the test. Moreover, even in this case, the membrane stress was not reduced. One possible reason is that water flow is localized and does not affect the interface delamination directly in the present model.

Presenting Author: Kazuaki Inaba Tokyo Institute of Technology

Authors:

Ibuki Mashio Tokyo Institute of Technology
Kazuaki Inaba Tokyo Institute of Technology