Design and Experimental Validation of a Micro-Newton Torsional Thrust Balance for Ionic Liquid Electrospray Thruster

Round 1

Reviewer 1 Report

This is a good paper, but needs significant editing for English language and style.  Here are a few recommendations to improve the clarity of the presentation:

All figure captions:  I recommend rewriting the captions so they are more informative.  The current captions generally just state what variables are plotted.

Figure 1:  I recommend changing the font color to white for the labels against the dark background. The FODS label is difficult to see in particular.

Lines 110-112:  Flexural pivots are not usually very robust under torques that are perpendicular to the flexure axis.  Is this a concern with having only one flexure which might experience these kinds of torques? Usually we include two flexures so they can't be bent.

Lines 141-142 and elsewhere:  The term "engagement displacement" is confusing--I was only able to understand what it meant by looking at the diagram in Figure 2. I recommend calling it something like "comb overlap."

Lines 147-148:  The PEEK base will electrically isolate the combs from ground, but will not screen out electric fields.  I recommend rewording this sentence.

Equation 9:  Discuss how well the coefficient for the V^2 term compares with what would be expected from Equation 8 and what physically causes the linear term.  Also, Equation 9 implies that there is a nonzero force with zero voltage. How is that possible?

Lines 190-192 and Figure 5:  Point out that these results are from tests without additional damping and were used to design the eddy current damper.

Lines 197-198:  It is not clear what is meant by substituting \omega_n and \xi into equation 2; should it be substituting in \xi, k, and I to determine c?

Line 234:  Typo--d_p > 6 mm and d_p > 6 mm

Figure 7:  Identify what the blue labels are.

Figure 10:  Include a legend indicating raw and filtered data lines.

Lines 306-308:  The effect of drift in calibrations can be eliminated by measuring the zero after each force level, rather than monotonically increasing or decreasing the calibration force. 

Figure 16 and lines 338-339:  What do the green error bars represent?

Reference 4:  Typos--should be Polk, J.E., Pancotti, A., ..., J. Prop. Power...

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors, congratulations for the good work. In the reviewer's report you can find a few suggestions that might improve the manuscript readability to the general reader.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf