| Summary: | 碩士 === 明志科技大學 === 機械工程系機械與機電工程碩士班 === 103 === The present study aimed to design a drug-delivery microneedle that could facili-tate painless drug administration using soluble materials exhibiting specific shapes and robustness. To achieve these specifications, ANSYS software was employed to ana-lyze the mechanical strength and lateral deflection critical load of the designs (pyra-mid column, triangular column, pentagon column and cone cloumn). The structural design was examined using the Taguchi method combined with critical buckling anal-ysis to identify the optimal size for the microneedle array.
Mechanical strength analysis showed that when applying the same pressure, the stress among each shape of the tip was near 70 MPa error of ± 0.5 MPa, it can not dis-tinguish the difference, buckling analysis showed that the buckling load of pyramid column is 0.117 N, triangular column is 0.091 N, pentagon column was 0.087 N and cone column is 0.068 N, The analysis results indicated that pyramidal column exhib-ited superior cirtical load strength.
An inclined exposure technique and micro molding method were used to fabri-cate the microneedle array. Carboxymethyl cellulose was selected as the constituents of the microneedle array. For the manufacturing process, the inclined exposure tech-nique was first employed in a laboratory to produce a pyramidal column-shaped sam-ple (base length = 320 μm, microneedle height = 650 μm, needle tip width = 15 μm) and an equilateral triangular column-shaped sample (base length = 396 μm, micronee-dle height = 650 μm, needle tip width = 15 μm). Then, high precision micro molding was employed using polydimethylsiloxane material to fabricate the female mold. Lastly, centrifugal casting was used to produce the microneedle structures.
Microneedles degradation test consists of in vitro and in vivo tests, in vitro tests using Hank solution asbhuman body solution, microneedle are completely degraded within a minute,in vivo test inserts microneedles into rabbit and observe the degradation, the result was showed that it’s completely degraded in twenty-five minutes. In needle buckling load tests when pyra-mid column is forced 0.307 N which produce buckling; triangular column is forced 0.1257 N which produce buckling.
Through this study confirmed that the pyramid shape needles have the better design of critical load and achieve the purpose of miceoneedles imme-diately degradation after piercing the skin.
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