Novel Extrusion System for the Encapsulation of Drug Delivering Bio-Medical Micro-Robots Presentation BY: Malcolm T. Gibson The University of Arizona Advanced Micro and Nano Systems Laboratory Dept. of Aerospace and Mechanical Engineering

Presentation Objectives Introduction Micro-Robotics Research Encapsulation Methods The Extrusion System Drug Delivery Mechanisms Discoveries Conclusion Acknowledgements

Introduction - Bio-Medical Micro-Robots Bio-Medical Micro-Robots are wireless devices for the remote delivery of drugs to systems within the human body. Future Applications include: –replacing high-risk intraocular surgeries. –Presenting an alternative to invasive cancer treatments. –Targeted Drug delivery IRIS - ETH Zurich

Micro-Robot Research Biomicrorobotics research is focused on building sub-mm sized, untethered robots for in-vivo medical applications. Areas of Research: - Structural Assembly - Electroplating - Drug Storage - Encapsulation - Bio-Polymers, Skin - Remote Actuation - Ultrasound - Diffusion - Magnetic Modulation - Robot Propulsion Building a complete robotic system that “swims” inside the human body is an advanced challenge and requires an innovative combination of Micro- and Nanotechnology. IRIS - ETH Zurich

Micro-Robot Encapsulation Encapsulation Purpose Drug Storage Drug Capacity Methods Dip Coating Soaking Extrusion Materials Sodium Alginate Sunflower Oil Co-fluidic robot extrusion system. The extrusion system utilizes drop formation via a capillary tip in a multi-phase laminar flow regime. It is designed to uniformly encapsulate micro-robots within a drug complex. Important Concepts Characterizing Flow Regimes Co-Laminar Flow Mechanics Reynold’s Numbers Ohnesorge Numbers Bond and Capillary Numbers Interfacial Forces

Micro-Robot Drug Storage Drug Storage - Methods and Materials Soaks for 5 min. Poly-l-lysine solution Soaks for 4 min. Polyethylenimine solution NaAlg./ HRP Droplet 15 Min. A B min. CaCl 2 solution Drug Substitute - Horseradish Peroxidase - 44,000 Da enzyme protein Drug Entrapment Matrix - Sodium Alginate - Cellulose fiber found in plant Cells - high strength and durability. Surface Skin Formation - Polymer Coating - Inhibits release prior to actuation Skin Bare

Drug Released (ng) Micro-Robot Actuation Actuation Mechanisms Diffusion - Bare Robots - Drug Limited by Area Magnetic Modulation - Magnetic Interference Ultrasound - Drug Encapsulation Drug Release vs. Time IRIS - ETH Zurich Drug Released (ng) Time (min.) Actuation

Discoveries and Conclusion ~ Thank you for your Attention ~ The University of Arizona Advanced Micro and Nano Systems Laboratory Dept. of Aerospace and Mechanical Engineering Ultrasound has been confirmed as a successful alternative Release mechanism for encapsulated micro-robots while presenting new Capabilities for controlled drug release.  The utilization of a dual-phase extrusion system allows increased uniformity and controlled variability of the encapsulation process.  By Encapsulating micro-Robots we can increase in the drug capacity and storage capabilities of the Micro-robot. 

Acknowledgement and Thanks Acknowledgement and Thanks to Dr. Eniko T. Enikov Principal Investigator and Mentor Advanced Micro and Nano-Systems laboratory Group For their help and guidance UA/NASA Space Grant Program For their support and research Encouragement ASU/NASA Space Grant Program For Organizing and Hosting the Statewide Symposium The Institute of Robotics and Intelligent Systems (IRIS) ETH Zurich - Switzerland The University of Arizona Advanced Micro and Nano Systems Laboratory Dept. of Aerospace and Mechanical Engineering