Different climbing robots relying on the use of polymer-based adhesives (PBA) have recently been prototyped. A common strategy used by these robots is to preload the PBA in order to maximize adhesion. This work focuses specifically on the behaviour of thin and slender PBAs under different loading conditions. A simplified two-dimensional analytical model of a slender PBA is developed by using a series of rigid links connected by revolute joints and torsion springs. It is assumed that a force is applied to one end of the slender PBA while the opposite end is fixed to a ground plane. The analytical model is validated with commercial software and subsequently used to investigate adhesion attachment. Parameters of the model are experimentally identified by using a PBA sample. An optimization is performed based on the developed analytical model and PBA shapes, which maximize preload, are identified.