AVS 46th International Symposium
    Biomaterial Interfaces Group Wednesday Sessions
       Session BI-WeP

Paper BI-WeP9
Microfabricated Cantilever Force Sensor for Measurement of Cell Locomotory Forces

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: B.W. Leslie, University of Glasgow, Scotland
Authors: C.D.W. Wilkinson, University of Glasgow, Scotland
A.S.G. Curtis, University of Glasgow, Scotland
B.W. Leslie, University of Glasgow, Scotland
Correspondent: Click to Email
Microfabricated cantilever force sensors are potentially capable of measuring attoNewton (10E-18 N) forces. Here, we propose a design for such a force sensor capable of measuring forces involved in cell locomotion. The cell guidance structures and cantilevers were fabricated as one integrated unit using dry-etching of polysilicon. Substrate used was a 300 µm thick (100) oriented silicon wafer coated on both sides with a 50 nm thick layer of silicon nitride. Wafers were cut into 25 mm squares. A 10 µm thick layer of isotropic polysilicon was deposited on one side of the wafer square. After patterning, the polysilicon layer was dry-etched to a depth of 10 µm to form cell guidance structures and a row of fifteen cantilevers along two opposing edges of the wafer square. Controlled etching of the silicon nitride layer ensured that cantilevers were released from the substrate while cell guidance structures remained in place. Cell guidance structures are designed to steer the cells toward the free end of the cantilever where deflection is largest for a given force. Cantilever dimensions (length=900 µm, height=10 µm, thickness=1 µm) combined with optical lever sensing of cantilever deflection are theoretically capable of measuring forces as small as 3 pN.