2.2.1 Glass Scoring, Drilling and Cleaning
Glass samples were scored to size with a diamond tipped pen and a ruler, or with the use of a tile cutter.
The glass was then broken along the score with glass plyers to the desired size.
Glass pieces requiring an electrolyte filling hole were marked with a permanent marker in the desired drill location; typical in the corner of a glass piece approximately 2.4 mm from the edge of the glass. A Dremel drill was mounted on a stage with a lever allowing for vertical movement of the drill. A 1 mm diamond tipped drill bit was placed in a drill and set to the lowest speed setting.
A single glass piece was placed in a petri dish and filled with water. The drilling was carried out under water to facilitate the transfer of heat and debris out of the drilling location. The marked drill location was lined up with the drill bit and the glass piece was held down with a polypropylene tweezer during the drilling the process. The drilling head was moved up and down during the drilling process to further facilitate the removal of the debris. Following drilling the glass pieces were rinsed with DI water before undergoing the cleaning process.
All glass pieces were placed in polypropylene carry trays before cleaning via a multistep ultrasonic cleaning process. First the glass pieces were immersed in soapy water and ultra-sonicated for 20 minutes.
Subsequently, the carry tray and glass was removed from the soapy water, rinsed with DI water, followed by an acetone rinse, before immersion in an acetone bath and ultra-sonicated for 20 minutes. Then, the glass pieces were rinsed with ethanol and immersed in ethanol bath and ultra-sonicated for a final 20 minutes. Finally, the glass pieces were removed from the final cleaning solution with tweezers and air dried from a compressed air stream.
2.2.2 Magnetron Sputtering
Magnetron sputtering of Pt, Au and Ti was carried out with Edwards Auto 306 magnetron sputter coater (West Sussex, United Kingdom) fitted with an Advanced Energy MDX 1.5K power supply (Colorado, United States) to provide the sputtering head power. A 40 Watt power setting was utilised with an argon
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plasma. The coating thickness was determined via a quartz crystal microbalance and an Edwards FTM6 film thickness monitor. Samples which were coated include microscope slides, ITO and FTO glass as well as polymer separators.
2.2.3 Cleaning and Surface Etching of Ti foil
Ti foil was purchased commercially as a roll and is cut to the desired size with a pair of scissors. The cleaning procedure for Ti foil consists of immersion and sonicated for 10 minutes in soapy water, rinsing in deionised water, followed by sonication for a second time in ethanol for 10 minutes. The Ti foil is further cleaned by immersing in 30 wt % nitric acid overnight to remove any remaining organic materials.
The Ti foil is finally rinsed with deionised water and air dried.
Surface etching of Ti foil is carried out in a glass vial containing 30 wt. % H2O2 on a hotplate in a fume hood. The Ti foil remains immersed for 20 minutes in solution at a range of temperatures before removal with polypropylene tweezers. The etching solution bubbles vigorously during the chemical reaction.
2.2.4 Adhering and Removing Ti and Surlyn
Ti foil can be adhered to Surlyn on a hotplate at 100 °C. To prevent contamination of the Ti foil with the hotplate, or to prevent the Surlyn from sticking to anything else during this process, the Ti and Surlyn are sandwiched between two pieces of Mylar (overhead transparency) as the Surlyn does not stick to this material. The Ti/Surlyn structure remains flexible. To make rigid Ti structures, the Ti is adhered onto glass or natural rubber with Surlyn also on a hotplate at 100 °C.
Ti foil can be delaminated from Surlyn via immersion in a THF:water mixture of 1:1 for 1 hour. A pair of tweezers can then be used to remove the Surlyn from the Ti foil. The development for adhering Ti foil onto flat surfaces and its delamination is covered in detail in Chapter 3 Section 4.2.
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2.2.5 Perforation of Ti Metal
In house laser perforation of 25 µm Ti foil was carried out on a Universal Laser Systems (ULS) PLS6MW Laser Engraver (Scottsdale, United States) that utilised a 150W 1.06 µm Fibre laser. Typical experimental conditions include a 30 % power level with nitrogen flowing through the nozzle and High Power Density Focusing Optics (HPDFO) lens. In house plastic jigs to hold the foils during perforation were made with the 10.6 µm CO2 laser. The development of the laser perforation of Ti foil and plastic jig supports is explained in detail in Chapter 3 Section 4.1.3.
2.2.6 Photo Lithography
Photolithography and etching of Ti foil with HF acid was carried out at the Centre for Quantum Computation and Communication Technology, Australian National Fabrication Facility (ANFF), University of New South Wales (UNSW). Ti foil was adhered onto natural rubber substrates with Surlyn, negative photoresist was spin coated on top and cured with UV photolithography. Following rinsing the Ti foil was immersed in 1:10 HF acid in water, contained within a Teflon beaker for the required time before rinsing with copious amounts of DI water. The photoresist could then be washed away and the samples inspected with an optical microscope. The development of the experimental process is covered in detail in Chapter 3 Section 4.2.
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