Micro Assembly
The preparation required for micro components at the design stage carries through all the way to automated assembly. Because the tolerances are critical and diminishing to microns and sub-microns, the stack-up tolerances of the micro components and their design criteria are scrutinized and their method of manufacturing are also considered for long-term production. The mechanics of micro assembly and the testing, inspection, application knowledge are required for fully functioning specks of dust working collaboratively and repeatedly. Handling these components is a challenge requiring high speed automation capable of handling dust speck sized parts, in-line metrology and vision systems to insure form, fit, and function, and positional accuracy to sub-micron tolerances. These joining/assembly methods include:
- AVOIDANCE OF HANDLING- Combining geometry into the least number of parts in a micro assembly
- TWO-SHOT MICRO MOLDING/OVER-MOLDING- Two-shot molding (2 injection barrels of two different materials) injecting into a mold at two different locations or in the same location with a rotating mold
- LASER WELDING- Careful control of laser energy and power densities can be used to selectively clean and strip materials such as wires quickly and non-destructively.
- ULTRASONIC WELDING-Very tiny (70-100 um) weld beads are possible with custom low energy boosters and ultrasonic horns.
- SOLVENT BONDING-Appropriate solvents must be used that are compatible with the materials being solvent bonded, especially if the assembly is to be used as an implantable.
- STAKING- Crimping or staking is a very common practice to generate good seals for preventing costly fluids from escaping the micro vessel.
Micro Molding
From napkin sketch to full CAD models, MES designs, manufactures, and assembles state of the art dust-specked sized micro molded parts and features. Concepts are provided to our clients comparing manufacturability and pros and cons in cost, scalability, quality, and handling/assembly. Examples of MES micro sized medical and drug delivery devices:
- Drug Compounded Polymer Stents, Anchors, Needles, and Sheaths
- Disposable Dry Powder Inhalers
- Diabetic Pumps with onboard micro valves
- Hydrogel, and collagen implants
- Micro Aspirators
- Neurosurgical coil assemblies
- Transdermal patches and drug well arrays
- Silicone micro intraocular implants
- Bio-Resorbable Polymer Implants
Micro Machining
MES designs, manufactures and assembles state of the are dust-speck sized micro molded parts and features with sub-micron tolerances, from initial concept to full CAD models. We work in a variety of fields with expertise in the medical and pharmaceutical industries.
One of the fastest ways to get micro parts in our customer’s hands has traditionally been micro machining. Many applications can be justified to spend capital on tooling up for micro molding, however, if the design has been made iteration-friendly (steel safe, inserted for areas thought to be changing prior to design freeze) then it may be a perfect candidate for micro machining.
Benefits to Micro Machining over other Micro Processes:
- Fast Parts in Hand to show feasibility
- Capital Cost Effectiveness in both low and high volume
- Features to 3 microns
- Surface finish to < 8 Ra
- Use of final material from prototype through production
Not all materials are friendly to micro machining, such as: some polymers, heat sensitive materials, and drug-induced materials. The shear stresses in which micro machining occurs can render a material degradable, physically weak, and/or unfit for sterilization in some cases.