Self-sensing cantilever

Piezoresistive readout can be utilized by using a piezoresistive cantilever, in which a sensing element (piezoresistor) is embedded at the clamped end thereby it is sometimes called a self-sensing cantilever (Fig. 4.3.3). In contrast to the optical readout method, no bulky and complex peripherals are required because a piezoresistive readout electrically measures the change in resistance of a piezoresistor with a simple circuit (Fig. 4.3.4). By means of the piezoresistive readout, it is also possible to perform measurements even in... 

Deflection detection schemes have been developed that use self-sensing piezoresistive cantilevers [104] or optical interferometry [105, 106]. But in nearly all practical systems cantilever deflection is measured with an optical lever system [107], as shown in Fig. 3.22. A small spot of laser light is reflected from the back of the cantilever and the reflected light is directed to an adjustable mirror. This in turn reflects the light onto a position-sensitive detector, a four-quadrant photo diode, shown schematically in Fig. 3.23. 

Wee, K.W., Kang, G.Y, Park, J., Kang, J.Y, Yoon, D.S., Park, J.H., et al., 2005. Novel electrical detection of label-free disease marker proteins using piezoresistive self-sensing micro-cantilevers. Biosens. Bioelectron. 20 (10), 1932-1938 (Proceedings paper). 

P. G. Ganesan, X. Wang, and O. Nalamasu, Method for sensing the self-assembly of polyelectrolyte monolayers using scanning probe microscope cantilever. Applied Physics Letters 89 p. 213107-213113 (2006). 

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