Title:
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Additive manufacturing of functional materials for polymer micro reactors
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This work investigates the development of functional materials by using additive
manufacturing techniques; specifically digital light processing (DLP) based
Stereolithography to manufacture micro reactors containing functional materials
for sensing and actuating devices in a single build. The envisionTEC Perfactory is a
DLP based Stereolithography machine (addressed as the DLP system) and has the
ability to manufacture feature size in the micron range with high precision. This
ability to manufacture small features with high precision is used for the
manufacture of polymer micro reactors.
Using the DLP system for processing functional composites is a novel approach.
The DLP system offers high resolution and accurate manufacture of parts. This
ability to process functional materials will be used for developing devices for
sensing and actuating applications.
In order to identify the feasibility of manufacturing composite of the DLP system,
barium titanate (BaTi03) ceramic was added to the photopolymer. The composites
containing up to 19 vol% BaTi03 as functional material were manufactured by the
DLP system. Poling these specimens showed a maximum piezoelectric coefficient
of 5 pC/N, measured at 30 MV /m and 90°C. Measuring ferroelectric properties of
these composite specimens showed a maximum remnant and saturation
polarisation of ±0.041 IlC/cm2 and ±0.359 IlC/cm2, measured at electric field of
249.97 kV/cm at room temperature.
As the parts were manufactured in layers; an investigation was undertaken to
identify the effect of build layer orientation on the mechanical properties. The
polymer specimens for the XY (horizontal) and the Z (vertical) build direction
showed strength of 39 MPa and 29 MPa, being achieved in the respective
specimen.
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