Adaptive Shell Spherical Reflector Actuated with PVDF-TrFE Thin Film Strain Actuators

Round 1

Reviewer 1 Report

This paper presents the design and manufacturing of a thin polymer spherical adaptive reflector of diameter D = 200 mm, controlled by a set of 25 independent electrodes arranged in a keystone  configuration actuating a thin film of PVDF-TrFE.

The results of the present study confirm that the active material can be described by a unidirectional quadratic model.

The paper is solid in simulation and experiment,  only English should be polished. Some terms such as " Control authority " are rarely used in control field, some revisions are needed.

Author Response

Thanks for your kind advice and we have refined the paper text. We have changed the word “control authority” to “shape control” as the name of the section 4.

Reviewer 2 Report

This paper reports on the development and research of the design and manufacture of a thin polymer spherical adaptive reflector, controlled by a set of 25 independent electrodes arranged in a keystone configuration actuating a thin film of PVDF-TrFE in d31-mode. The piezoelectric parameters and quasi-static characteristics of the proposed adaptive shell spherical reflector, it’s   shape control with an array of independent electrodes is analyzed theoretically as well as experimentally.  It will contribute to progress in applications of the proposed multilayer adaptive thin shell reflectors for future space technologies. The paper is written reasonably well and good structured, the design and the manufacturing methodology of the demonstrator is described with enough detail for fabrication.

Overall, I find the paper to be useful and well-executed. There are a few items that need attention. Specific comments and questions needing attention are provided below.

Specific Comments:

Page 2, lines37, 38:  a parameter, ρ - electrode size, used in the text should be explained.

In figures 6, 7 and 8 the characteristics W and PV are presented and analyzed; what are differences between these characteristics.

In Conclusions is stated: … better circular symmetry indicates a clear improvement in the manufacturing process, as compared to a previous study. Some quantitative data should be given to support your viewpoint.

Next statement: … the reconstructed optical modes are achieved with reasonable voltages…        The value of the “reasonable” voltages should be given.

Author Response

Thanks for your kind advice and we have made following revisions according to your suggestions:

(1) We add a note of definition after the text “electrode size ρ” with “(estimated by ρ = 4A/L_C, A is the electrode area and L_C is the perimeter of the electrode profile)”

(2) W is the surface displacement and PV is the Peak-to-Valley of deformation, we add the definition of PV in the abbreviation table of the paper.

(3) The quantitative illustrations have been given as Figure 6 (to show a better circular symmetry), which should be compared to Figure 15 of Ref [10]; a sentence is added in the conclusion.

(4) We add additional information after the text “reasonable voltages” with “(∆V < 100V, compliant with the ESA specifications)”.