Microloading Effect

1. Microloading Effect Demonstration of microloading effect where etch depth increases with trench width. Image is of 10 µm deep Si using RIE with Cl/ F chemistry.

2. Bosch process Deep reactive ion etching (DRIE) using Bosch process enables high aspect ratio structures

3. Deflection-based sensors Each cantilever is functionalized on one side with a different oligonucleotide base sequence (red or blue). (A) The differential signal is set to zero. (B) After injection of the first complementary oligonucleotide (green), hybridization occurs on the cantilever that provides the matching sequence (red), increasing the differential signal Delta x. (C) Injection of the second complementary oligonucleotide (yellow) causes the cantilever functionalized with the second oligonucleotide (blue) to bend. Array of cantilevers used as deflection sensors for chemical solvent vapors. Cantilevers are coated with different polymers in order to define a particular set of responses based on how each polymer responds to a given analyte. Science 14 April 2000: Vol. 288. no. 5464, pp. 316 - 318

4. Resonance-based sensors Gold dot 2 um 5 um Nanoscale gold dot can be used with thiol-based chemistries to localize analyte binding. This device is capable of detecting attogram quantities of thiol-terminated SAMs SEM image of single E. coli bound on cantilever tip. This cantilever measured the mass of a single cell to be 665 fg

5. Nanostring resonator Doubly-clamped nanomechanical resonator defined nonlithographicall where electrospun fibers are used as etch mask.

6. Cantilever Array Arranging cantilever-based sensors into arrays allows detection of multiple analytes from a single sample

7. Resonance peaks from resonance-based sensors Example of resonant peaks measured between reaction steps in the detection of virus particles. Before and after virus-specific antibody layer deposition Resonance peak after virus binding