A Disposable Dispensing Valve for Non-Contact Microliter Applications in a 96-Well Plate Format

We present a miniaturized, disposable, normally-closed electromagnetic dispensing valve for the microliter range to process 96-well plates. The novel injection-molded valve is designed to fit into a 9 mm grid to realize an eight channel dispensing head, enabling the serial processing of well plates row-by-row. The presented dispensing valve design originates from a miniaturization study of a previously developed functional model. The outer diameter of the valve, including all actuating components, was reduced by 8 mm to an overall diameter of 8.5 mm without compromising the performance. Additionally, the actuation current of the valve could be reduced to 5 A. The valve is characterized for a volume range between 840 nL and 5.3 μL. The performance of the injection molded valve is competitive to commercially available dispensing valves, featuring the advantages of low fabrication costs, disposability, low mounting size, easy handling, and super silent actuation

A Disposable Dispensing Valve for Non-Contact Microliter Applications in a 96-Well Plate Format

We present a miniaturized, disposable, normally-closed electromagnetic dispensing valve for the microliter range to process 96-well plates. The novel injection-molded valve is designed to fit into a 9 mm grid to realize an eight channel dispensing head, enabling the serial processing of well plates row-by-row. The presented dispensing valve design originates from a miniaturization study of a previously developed functional model. The outer diameter of the valve, including all actuating components, was reduced by 8 mm to an overall diameter of 8.5 mm without compromising the performance. Additionally, the actuation current of the valve could be reduced to 5 A. The valve is characterized for a volume range between 840 nL and 5.3 μL. The performance of the injection molded valve is competitive to commercially available dispensing valves, featuring the advantages of low fabrication costs, disposability, low mounting size, easy handling, and super silent actuation

Novel Artificial Urinary Sphincter for Stress Urinary Incontinence Treatment

University of Minnesota M.S.E.E. thesis. September 2017. Major: Electrical Engineering. Advisor: Gerald Timm. 1 computer file (PDF); xiv, 129 pages.The American Medical System’s AMS 800TM has been the gold standard for over 40 years with over 150,000 patients treated for Urinary Incontinence and is the leading treatment for male stress urinary incontinence (SUI) following prostate surgery. Type III SUI, or intrinsic sphincter deficiency, is the inability of the urethra to maintain closure pressure sufficient to keep the patient clinically dry at rest and during periods of heightened activity (~120 cmH2O; coughs, sneezes, posture changes, and exercises). The current AMS 800TM is not personalized to a patient’s needs and compromises with an in between pressure- as high (61-70 cmH2O) as it can be without exceeding safety threshold levels. As such many men still leak when they are active. The market is hungry for a device that can adapt to the patient’s level of activity, reducing pressure most of the day to protect the urethra and then briefly increasing the pressure when he is more active. We are developing a novel implantable pump (henceforth called “add-on device”) which will be an add-on to the AMS 800TM and it includes a solenoid coil-cum-plunger and a fluid reservoir within the pump body. The add-on device will be small, light-weight and battery powered, and maintain compatibility with the AMS 800TM device. The device idea is in its proof-of-concept stage. This add-on device can be a possible solution to reducing the risks including urethral atrophy (leading to return of incontinence) and erosion (leading to infection of the implant) resulting from the constant pressure

Printing cells and co-cultures for osteoarthritis models

PhD ThesisOsteoarthritis is a multifactorial disease characterised by the degradation of cartilage and bone tissue within the joint. Research into novel therapies is currently limited by the throughput and replicative accuracy of early-stage in vitro disease models. Biofabrication represents an emerging technology which allows for the selective deposition of cells and material in order to create complex cell-laden structures. The aim of this research was to characterise a combination of inkjet and valve-based drop-on-demand printing processes for the construction of osteoarthritis tissue models. An inkjet printing platform was characterised to deposit material at the picolitre-scale. Single cell printing was achieved, with biological analysis confirming that the printing process does not significantly affect cellular viability or function. A valve printing process was applied for the production of cellular aggregates that could be used for both in vitro osteoarthritis research and in vivo therapeutic applications. Reliable jetting performance was demonstrated, enabling material deposition at the nanolitre-scale. Cell printing was achieved across a concentration range of 1-20 million cells per mL, with biological analysis of printed cells revealing no significant effects on viability or function. No discernible impact on aggregate tissue structure was observed as a result of the printing process, confirming its suitability for the manufacture of tissue aggregates. A bioprinted co-culture tissue model comprised of mesenchymal stromal cell and chondrocyte cell types was successfully generated using a 3D insert culture format. Cell proliferation was maintained over a 14 day period, alongside an increase in tissue density and cellular organisation. In combination, this research has demonstrated the suitability of inkjet and valve printing processes to selectively deposit cells. Bioprinted aggregate and insert-based 3D tissue models were validated using the valve printing technique, providing an effective method to scale up the manufacture of in vitro platforms for osteoarthritis research applications.Versus Arthritis, the Engineering and Physical Sciences Research Council and the Centre for Doctoral Training in Additive Manufacturing and 3D Printin