was inserted into a microchannel and the protein molecules were allowed to adsorb onto the channel surface. Thus, the effect of diffusion was expected to be small because of the non-flow condition within the channel. Adsorption resulted in alteration in surface energy and consequent deformation of the channel wall. Fig.  decreased to 40 o . This adsorption was nevertheless reversible, because the protein molecules could be desorbed completely by flowing in aqEth followed by water through the channel for sufficient time, so that W  was found to increase to 107 o same as that for a fresh PDMS and  too increased and attained that corresponding to pure water (Figure ). In essence, the protein molecules interacted with the PDMS surface via physical forces and didn't get chemically bonded on it. In Fig. , we plot  with time of adsorption, Ads t to show that rate of change of  with time was initially large, but diminished over time (over @5 hours). It can be considered that initially, the number of adsorption sites on the surface of the channel wall far exceeds the concentration of protein molecules in liquid at the vicinity of the wall   Ads 0 t P  , so that, the rate of adsorption does not depend on the surface concentration of adsorption sites, but only on protein concentration. Over time,   P decreases because of adsorption on the channel surface; along with it, the intrinsic adsorption rate too decreases. So, at the initial stage, in the limit that the rate of diffusion of the protein from the bulk to the surface << intrinsic rate of its adsorption, this rate can be expressed by first order kinetics as,     shows this plot, from the slope of which, UV Ads k was obtained as 0.42 hr -1 . While this value corroborated well with that from elasto-capillary effect, more experiments can be done in combination with other methods, to gain mechanistic insight to the adsorption process. It is worth noting also that the occurrence of the absorption band at ~208 nm has been reported also by others in the literature and has been attributed to the