Strain detection for automated nano-manipulation
A strain detector for in-situ lift-out, comprises a nano-manipulator probe shaft; a strain gauge mounted on the probe shaft; and a first cut-out on the probe shaft. The first cut-out has a rectangular cross-section. There is a second cut-out on the probe shaft; the second cut-out having a semicircular cross-section. The second cut-out is positioned on the shaft opposite from the first cut-out; the first and second cut-out, thus defining a thinned region in the probe. The strain gauge is mounted on the probe shaft at the location of the thinned region. There is detecting circuitry for detecting, amplifying and conditioning the output of the strain gauge; and, wires electrically connecting the strain gauge to the detection circuitry. The wires are preferably located in a trench in the probe shaft. Other embodiments are disclosed having multiple strain gauges and detectors.
1. A strain detector for in-situ lift-out, comprising:
a probe shaft;
a first cut-out on the probe shaft;
a second cut-out on the probe shaft, the second cut-out opposite from the first cut-out; the first and second cut-outs defining a first thinned region in the probe shaft;
a first strain gauge mounted on the probe shaft at the location of the first thinned region;
a third cut-out on the probe shaft;
a fourth cut-out on the probe shaft, the fourth cut-out opposite from the third cut-out; the third and fourth cut-outs defining a second thinned region in the probe shaft;
where the first and third cut-outs have a triangular cross-section;
a second strain gauge mounted on the probe shaft at the location of the second thinned region;
where the second strain gauge is located substantially perpendicular to the first strain gauge.
2. The strain detector of claim 1 , where the first and second strain gauges are resistance-based strain gauges.
3. The strain detector of claim 2 , where the first and second strain gauges are silicon strain gauges.
4. The strain detector of claim 3 , further comprising:
detection circuitry for detecting, amplifying and conditioning the output of the first and second strain gauges; and,
wires electrically connecting the strain gauges to the detection circuitry.
5. The strain detector of claim 4 where the detection circuitry comprises at least one Wheatstone bridge.
6. The strain detector of claim 2 where the resistance-based strain gauges are each smaller in cross-sectional area than one square millimeter.
7. The strain detector of claim 2 ,
where the surface of the first cut-out and the third cut-out comprise an adhesive for mounting the first and second strain gauges respectively to the probe shaft.
8. The strain detector of claim 7 , where the adhesive is epoxy.
9. A strain detector for in-situ lift-out, comprising:
a probe shaft;
a first cut-out on the probe shaft;
a second cut-out on the probe shaft, the second cut-out opposite from the first cut-out; the first and second cut-outs defining a first thinned region in the probe shaft;
a first strain gauge mounted on the probe shaft at the location of the first thinned region;
a third cut-out on the probe shaft;
a fourth cut-out on the probe shaft, the fourth cut-out opposite from the third cut-out; the third and fourth cut-outs defining a second thinned region in the probe shaft;
where the second and fourth cut-outs have a semi-circular cross-section;
a second strain gauge mounted on the probe shaft at the location of the second thinned region;
where the second strain gauge is located substantially perpendicular to the first strain gauge.