A new approach to collagen fiber orientation in cow skin by the microwave method

The fiber orientation of cow leather sheets corresponding to the corium of the middle layer in the cow skin was studied by measuring the angular dependence of transmitted microwave intensity and the complex dielectric constant at a microwave frequency of 3.9 GHz. The direction of the minimum transmitted microwave intensity and the maximum dielectric loss agrees with that of the maximum mechanical breaking strength, suggesting that the collagen fibers constituting the cow leather should be preferably oriented in the direction of minimum transmitted microwaves and the maximum dielectric loss. The electron microphotograph supported this suggestion. The main chain direction of collagen fibers and the degree of orientation varied from position to position in the sheet. The present microwave method is convenient for quick determination of the orientation of collagen fibers in the cow skin. It can be applied non-destructively and contact-freely.