Deborah Ohiani-Jegede Partners: Nkele Davis and Nick Xydis Group 24 , Client :Brad Clay, bio Merieux Biofilms are an aggregate of microorganism where cells are stuck to each other and/or a surface Can form contact lens cases due to improper cleaning/user noncompliance Contact lens contamination can lead to microbial keratitis, conjunctivitis, staphylococci which may require surgery Usability Within 3” x 5” Weight: < 5 lb Operating time: < 1 hours Visual timer display Set up Time: < 30 seconds Sound during application: < 40 dB Autonomous system, turns on and off automatically Waterproof Economics Effectiveness Cost: < $200 (prescribed by doctor) Power Draw: < .25kWhr per application 95% biofilm destruction biofilm growth prevention No damage to lens case and lens Durability meets all other specification requirements after 5 years Choose Disinfection Technology Disinfection Technologies Construct Final Product Design Hydrogen Peroxide Solutions Heat Treatment Pulsed Electric Field Ultraviolet Radiation Sonication Atmospheric Pressure RoomTemperature Plasmas UV-C radiation (100-280nm) effectively stunts biofilm growth Penetrates bacteria to nucleus to irreversibly damage the DNA 254nm breaks molecular bonds of microsomal DNA High frequency shaking (sonication) can disrupt biofilm by breaking up extracellular matrix and dislodging from surface Coupled with another method, could potentially make disinfecting more effective Sonication at 40kHz for 5minutes had success in previous literature Apply high voltage between dielectric electrodes to ionize surrounding air Reactive oxygen species (O3, H202, O2, OH-) destroys biofilms via oxidation “Plasma needle” – high voltage to metal wire to ionize surrounding air Tested UV radiation, UV + Sonication, Cold Plasmas Staph epidermidis - test bacteria o o o Common microbe on contact lens and contact lens cases Biofilm forming strain chosen Diluted bacteria to 1McFarland (3e8 bacteria/mL) Testing on polystyrene coverslips o Common plastic in contact lens manufacturing UV-C radiation at 254nm produced using MaxLamp FIlter Three five-minute treatments biofilm on coverslip Streaked samples on agar plates in between trials Plates grown overnight in incubator at 36°C Extremely effective in destroying biofilms Solution added to coverslip to prevent drying/warping Prepared coverslip, placed in ultrasonic cleaner, and weighted down with bottle Treated for 5 minutes at 40kHz, then with 5 min UV Cycle repeated 3 times total Swab and plate samples after each treatment Plates grown overnight in incubator at 36°C Small hole bored into petri dish cover contain plasma Generator at 30kV Three five-minute treatments of plasma Swab and plate samples after each treatment Plates grown overnight in incubator at 36°C Weight Ultraviolet Radiation Ultraviolet Radiation + Sonication Cold Plasma Efficacy 5 5 3 3 Safety 4 4 4 3 Durability 4 4 3 3 Cost 3 3 2 4 Speed of Use 2 5 4 3 76 57 57 TOTAL UV+Sonication Plasma Motor engine to sonicate Deep UV light Single Button Timer Display Safety Interlock Door sensors LED Light Minimal light intensity of 30 microWatts/cm2 30-minute application Side Panel Access Door Nkele o o Deborah o o Sonication and Mechanical Turbulence Expert Lead Ergonomics Designer UV Treatment and Biofilm Growth Expert Lead Mechanical Designer Nick o o Plasma and Electric-Field Treatment Expert Lead Electrical Designer November o o o o o o o o o o o o o 2nd - Optimizing Physical Design 4th - Performing UV Wavelength Testing 5th - Continued Wavelength Testing 6th - Ensuring Optimal UV Application Technique 7th - Evaluation of Experimental Results 8th - Meet with Manufacturing 10th - Computer Model of Design 13th - Brainstorming compatible materials 15th - Creating official List of Materials 16th - Design Verification 22nd - Final Paper Draft 28th - Thanksgiving 29th - Final Paper Revision December o o o 2nd - Final Presentation 4th - Final Report Due 5th - Celebratory Retreat Questions?