Introduction
Concept
Experiments
Optical system for irradiating with patterned light
Software configuration
Homogenization of the light intensity
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Input a white image to the DMD.
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Measure the intensity distribution of a light reflected from the DMD (\(I_{x, y}\)) by using the laser profiler.
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Use the following Eq. (1) to determine a reflection rate of each pixel of the DMD.Here, \(r_{x, y}\) is reflection rate of an input image at pixel (x, y) and \(I_{min}\) is the minimum value of the measured intensity distribution among all pixels. Because \(I_{x, y}\) means intensity distribution of the reflected laser, the values \(I_{min} / I_{x, y}\) give reflection rate for each pixel to suppress intensities to \(I_{min}\) for all pixels.$$\begin{aligned} r_{x,y} = I_{min} / I_{x,y} \end{aligned}$$(1)
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Finally, we can acquire homogenized reflected laser with minimum intensity values by inputting intensity values multiplied by \(r_{x, y}\) to the DMD.
Fabrication
Results and discussion
Calibration and evaluation of the position of the patterned light
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Irradiate the square shape with a side length of 30 \(\mu\)m to four corners and center of the irradiation area (Fig. 6a) and capture the image.
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Process the binarization of the captured image (Fig. 6b).
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Calculate the center of each irradiation area.
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Compare the acquired center of the area and the input values.
Resolution of the generated light pattern
Evaluation of the switching responses of the light irradiation
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Send an image to the DMD N times with various frequencies
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Measure the sending time and define it as T.
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At each frequency, count the number of trials if T is within the cycle time and define the number as \(N_S\).
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Calculate the success rate \(A=N_S / N\).
Homogenization of the light intensity
Before | After | |
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CV | 0.153 | 0.066 |
Max. | 3251 | 1509 |
Min. | 980 | 809 |
\(R_h\) | 0% | 20% | 40% | 60% | 80% | 100% |
---|---|---|---|---|---|---|
C. V. | 0.153 | 0.149 | 0.146 | 0.100 | 0.067 | 0.066 |
Max. | 3251 | 3080 | 3116 | 2383 | 1497 | 1509 |
Min. | 980 | 995 | 981 | 947 | 821 | 809 |
Using the constructed system to drive gel actuators
Homogenization rate \(R_h\) | ||||||
---|---|---|---|---|---|---|
0 % | 10 % | 20 % | 30 % | 40 % | 50 % | |
C. V. | 0.83 | 0.82 | 0.88 | 0.73 | 0.67 | 0.24 |