Bio-MicroElectroMechanical Systems (BioMEMS) – microfabricated sensors, actuators and microfluidic and lab-on-chip systems- is an emerging field that targets to develop miniaturized devices for the diagnosis, monitoring and treatment of diseases as well as to provide enabling tools to researchers in the life sciences. In the past few years, three dimensional (3D) printing technology has also joined the effort of miniaturization with high resolution 3D printers capable of fabricating micrometer scale objects. Furthermore, the increase in material choice has led to an explosive growth in microfabrication technology based biomedical applications. This research, divided into two parts, describes the development of 5 novel Bio-Micro-System devices. The term Bio-Micro-System has been used here to describe BioMEMS and 3D printed devices, with the dimensions of key components ranging from micrometers to a millimeter. Part A is focused on ‘Medical’ Micro-System devices that can potentially solve common medical problems. Part B is focused on ‘Biological’ Micro-System devices/tools for facilitating/enabling biological research.

PART A- Medical Micro-Systems

- Two implantable, electronics-free, IOP microsensors for the medical management of glaucoma. 1) Near Infrared Fluorescence-based Optomechanical (NiFO) technology: Consists of an implantable, miniaturized pressure sensor that ‘optically encodes’ pressure in the near infrared (NIR) regime. A non-implantable, portable and compact optical head is used to excite the sensor and collect the emitted NIR light. The thesis discusses optimized device architecture and microfabrication approaches for best performance commercialization. 2) Displacement based Contrast Imaging (DCI) technology: A proof of concept, fluid pressure sensing scheme is shown to operate over a pressure range of 0–100 mbar (∼2 mbar resolution between 0–20 mbar,∼10 mbar resolution between 20–100 mbar), with a maximum error of <7% throughout its dynamic range. The thesis introduces the technology and discusses its application as an IOP sensor.

-A Touch-activated Sanitizer Dispensing (TSD) system for combating community acquired infections. The TSD can be mounted on any surface that is exposed to high human traffic (eg. door handle) and consists of an array of human-powered, miniaturized valves that deliver a small amount of disinfectant when touch actuated. The device disinfects the person’s hand that is touching it while being self-sterilized at the same time. The thesis describes the design and implementation of a proof of concept TSD that can disinfect an area equivalent to the size of a thumb. A significant (~ 10 fold) reduction in microbiological load is demonstrated on the fingertip and device surface within the first 24 hours. The size and footprint of the TSD can be scaled up as needed to improve hand hygiene compliance.

PART B- Biological Micro-Systems

-A cryo-anesthesia microfluidic chip for immobilizing Drosophila melanogaster larvae. We developed a microfluidic chip for immobilizingDrosophila melanogaster larva by creating a cold micro-environment around the larva. After characterizing on chip temperature distribution and larval body movement, results indicate that the method is appropriate for repetitive and reversible, short-term (several minutes) immobilization. The method offers the added advantage of using the same chip to accommodate and immobilize larvae across all developmental stages (1st instar-late 3rd instar). Besides the demonstrated applications of the chip in high resolution observation of sub cellular events such as mitochondrial trafficking in neurons and neuro-synaptic growth, we envision the use of this method in a wide variety of biological imaging studies employing the Drosophila larval system, including cellular development and other studies.

-A 3D printed millifluidic device for CO2 immobilization of Caenorhabditis elegans populations. We developed a novel 3D printed device for immobilizing populations of Caenorhabditis elegans by creating a localized CO2 environment while the nematodes are maintained on the surface of agar. The results indicate that the method is easy to implement, is appropriate for short-term (20 minutes) immobilization and allows recovery within a few minutes. We envision its usage in a wide variety of biological studies including scoring lifespan assays and fluorescence imaging applications.

Date: Wednesday, January 10, 2018
Time: 12:30 PM
Location: 2203 LBME
Chair: Dr. Nikos Chronis