Skip to main content
. 2012 Nov 30;7(11):e50443. doi: 10.1371/journal.pone.0050443

Figure 4. Surface non-specific adhesion of E cell islands measured using a micro-fabricated bio-MEMS force sensor.

Figure 4

(a) The non-functionalized micro-fabricated Si force sensor with a flat probe and with known force-deflection relation is manipulated by a high-resolution x-y-z Piezo-stage to contact cell islands' lateral convex surface (on x-y plane). (b) Confocal microscopy of cell islands show the height of islands is on the order of 30∼50 μm. The vertical height of bio-MEMS probe is 5∼10 μm. (c) After a 2-minute contact, force sensor is horizontally pulled away at a constant speed of 2.1±0.4 μm/s. While the cell adhesion between the probe and cell surface hinders retraction of the sensor, the sensor beams deform by δ, giving the force F. Note that the probe is not functionalized. The 2-minute contact between the probe and cells prevents the activation of cell integrins and the formation of any cell focal adhesion, which takes >30 minutes to form.