The present invention concerns compositions containing carbohydrate derivatives for enhancing the skin barrier function. The system includes one or more standoffs that are each received through appropriately formed corresponding openings through a printed circuit board. To ensure accurate estimation results, certain persistent excitation criteria may be met. The composition further comprises preferably a primary or secondary amine. When folded down, the respective attachment elements can be integrated into the respective side wall element in such a manner that the attachment elements at least will not protrude substantially over the thickness of the side wall elements.