Analysis of full and cross-shaped boss membranes with piezoresistors in transversal strain configuration

Abstract

A 3D force sensor is developed using bulk silicon micromachining for measuring force in the sub-µN range. It is intended for use in high precision coordinate measuring machines. Full and cross-shaped boss membranes are fabricated, where the total chip size is 6.5 × 6.5 mm 2 . The full membrane is 3000 × 3000 µm 2 and the beams of the cross-shaped membrane are 900 × 700 µm 2 with 16 p-diffused piezoresistors in transversal strain configuration. The strains detected by the piezoresistors are measures of the three orthogonal components of the force applied at the tip of the stylus, which is glued on the center of the boss. When a vertical load is applied to the stylus, higher sensitivity is obtained for the cross-shaped membrane than for the full membrane.

Integration of a piezoresistive microprobe into a commercial gear measuring instrument

“…The membrane bridges oriented parallel to the deflecting force deliver a signal change with an opposite sign. The other two bridges are under torsion, which induces no signal changes [22]. As a consequence of this working principle [20,22,23,26,30], the four measured voltages can be transformed into three theoretical main axis signals ′, ′, ′ with the help of the matrix (Eq.…”

“…In previous characterization experiments [27], very little cross talk was observed and least squares fits revealed non-diagonal elements in % with values in the range of only 0.1 -4.5 % of the diagonal elements. In practice, however, measurements on the GMI do not differ whether diagonal elements are considered or not and all non-diagonal elements of % can be set to zero [22][23][24]26].…”

“…It provides a repeatability of 4 nm and probing forces down to 0.01 mN [16][17][18]. The silicon-membrane-based microprobe used in this work has been developed at the Technische Universität Braunschweig (TU Braunschweig) in cooperation with PTB [19][20][21][22][23][24]. Depending on the probing direction, this microprobe provides a resolution of 3-5 nm and a repeatability of 10-20 nm with a stiffness of 1-20 mN•µm -1 [19,23].…”

Micro force plate array for measurement of ground reaction force of insect running

“…Conventional multi axes force sensors are composed of sensing beams and a probe column at the center of the beams [3][4][5]. Capacitance or piesoresistive elements are formed at each beam, and the beam deformations are detected.…”

Compliant Tactile Sensors for High-Aspect-Ratio Form Metrology

“…In recent years coordinate measuring machines (CMM) have been constructed for direct metrological characterization of high aspect-ratio microstructures (Bos et al, 2004;Bos et al, 2007;Küng et al, 2007;Peggs et al, 1999;Seitz, 2005;Tibrewala et al, 2008). For narrow holes actively sensing probing elements were developed which were scaled down to diameters of 120 -300 µm.…”