PERANCANGAN SISTEM KENDALI PADA ALAT LIQUID HANDLING SYSTEM (LHS) 3-AXIS MODIFIKASI MESIN 3D PRINTING FUSED DEPOSITION MODELING (FDM)

DESIGN OF A CONTROL SYSTEM FOR A 3-AXIS LIQUID HANDLING SYSTEM (LHS) MODIFIED FROM A 3D PRINTING MACHINE USING FUSED DEPOSITION MODELING (FDM)

    Perkembangan Sistem pipetting manual masih sering digunakan, sehingga berisiko terhadap kontaminasi akibat kontak langsung dengan tangan manusia. Liquid Handling System (LHS) merupakan solusi otomatis untuk meningkatkan efisiensi dan mengurangi risiko kontaminasi, tetapi harganya mahal karena sistem kendali dan mekaniknya yang kompleks. Oleh karena itu, penelitian ini mengembangkan prototipe LHS dengan memanfaatkan mesin 3D printing tipe fused deposition modeling (FDM) berbasis sistem gerak kartesius pada sumbu X, Y, dan Z, sehingga menjadi lebih ekonomis dan efisien. Penelitian ini menggunakan metode research and development (R&D) yang meliputi pengembangan desain, pembuatan prototipe, uji coba, dan analisis data. Sistem kendali dirancang berbasis open-loop menggunakan Arduino Nano ATmega168 sebagai pengendali utama, dan ESP32 untuk komunikasi Bluetooth antara joystick dan gerakan LHS. Variasi kecepatan motor stepper (High, Medium, dan Low) diuji untuk mengevaluasi pengaruhnya terhadap kecepatan dan akurasi pipetting. Motor stepper NEMA 8 digunakan sebagai aktuator utama, dengan dukungan CNC shield dan driver motor stepper. Hasil penelitian menunjukkan bahwa kecepatan Low dan Medium menghasilkan stabilitas volume cairan yang baik (2,71–12,29 mL dan 2,96–12,42 mL), sedangkan kecepatan High memberikan throughput lebih tinggi (4,25–17,21 mL), tetapi kurang stabil pada step angle besar. Prototipe ini direkomendasikan untuk aplikasi pipetting dengan penyesuaian kecepatan berdasarkan kebutuhan akurasi atau throughput.

Manual pipetting systems are still widely used, posing a risk of contamination due to direct contact with human hands. The Liquid Handling System (LHS) offers an automated solution to improve efficiency and minimize contamination risks. However, its adoption is often hindered by the high cost associated with its complex control systems and mechanics. This research aims to develop a more economical and efficient LHS prototype by utilizing a 3D printing machine with a fused deposition modeling (FDM) method, based on a Cartesian motion system in the X, Y, and Z axes. The research employs a research and development (R&D) methodology, encompassing design development, prototyping, testing, and data analysis. The control system is designed as an open-loop system using an Arduino Nano ATmega168 as the primary controller and an ESP32 for Bluetooth communication between the joystick and the LHS movements. Stepper motor speed variations (High, Medium, and Low) were tested to evaluate their effects on pipetting speed and accuracy. A NEMA 8 stepper motor was used as the main actuator, supported by a CNC shield and stepper motor driver. The results demonstrated that Low and Medium speeds provided good liquid volume stability (2.71–12.29 mL and 2.96–12.42 mL, respectively), while High speed delivered higher throughput (4.25–17.21 mL) but exhibited reduced stability at larger step angles. This prototype is recommended for pipetting applications where speed adjustments can be tailored to prioritize either accuracy or throughput, depending on specific requirements.