Micro Ophthalmic Technology
10/28/15 Micro manufacturing is a major component in new cutting edge medical and pharmaceutical technology. Usually the smallest component in a medical or pharmaceutical implant or device is the enabling component. One popular field for micro is ophthalmic due to age related eye diseases (cataracts, diabetes, glaucoma, etc). Ophthalmic and intraocular implants are largely made up of many micro sized and highly precise components and assemblies. This market sector continues to remain one of the largest and fastest growing micro medical and pharma micro device sectors, globally. Anyone who has ever had a speck of dust in their eye knows the irritation it causes, so imagine how small eye implants and devices must be in order to be comfortable to wear.
Intraocular implant
Another common eye problem is Dry Eye. It is an irritation of the eye due to an ability to produce enough tears to keep the eye comfortably moist. Treating this condition generally requires micro components about ¼ of the size of a grain of rice put inside of a punctal plug. This plug is surgically placed in both the upper and lower eyelids to prevent fluid in the eye from draining.
In the micro field we are exploring new alternatives to existing medical and pharmaceutical devices and procedures. Just imagine sometime in the future giving a blind person the ability to see for the first time or putting a contact lens in your eye that has a computer screen on it, these ideas are already in the research phase and could become a reality soon! The options of using micro capabilities in the medical and pharmaceutical fields are endless. We here at Micro Engineering Solutions are using cutting edge technology and research to help move these fields into the future!
Artificial Skin That Provides a Sense of Touch
10/21/15 Stanford scientists have developed a pressure sensor that could be turned into artificial skin that would go over prosthetics, allowing people to feel objects as they touch them. The sensors send pulses to the brain that are interpreted as “touching”. It mimics our biological system.
The skin is made of plastic, imprinted with a waffle pattern so it compresses. Embedded inside the skin are tiny cylinders of pure carbon that conduct electricity. When the material is squeezed, the rods get closer together creating rapid pulses as the pressure increases. The end goal is to channel information from artificial sensors into the peripheral nerves that were once connected to the lost hand.
This advancement would not be possible without micro technology. Micro plays a crucial role in todays medical and pharmaceutical fields.
Micro Molding Needles and Sharps
10/15/15 Micro molded Needles and Sharps are very advantageous in the following areas: disposability, recyclability, ease of use, and cost effectiveness. They are being used in applications such as cost-effective vaccine delivery, glucose monitoring and insulin delivery devices, transdermal wearable drug patches, and automatic blister or capsule drug puncturing just to name a few. They are designed and developed in many different forms; transdermal patches, staples, singular needle sites, anchors, forceps, and cannulas. They are manufactured and processed using several micro manufacturing methods; micro molding, micro milling, etching, laser machining, embossing, and forming.
Needle compliance is defined as a needle with the least amount of pain inflicted on the patient AND the ease of use of the device for both patient and surgeon. Compliance can also be taken to the microscopic level (as seen in the image below) which shows the body’s reaction (in this case a cell) to foreign body (the needle) that has been inserted into it. The cell or even the skin will react to the puncture of needles by sending white blood cells to that area immediately as the army of protection comes to the aid of the skin or surrounding cells/organs. This phenomenon is baffling to glucose monitoring device engineers and researchers as these extremely fast responses are measured automatically and in some cases falsely administer insulin unnecessarily.
Cellular response of White Blood Cells to Needle Penetrating it (Foreign Body)
In order to provide the least amount of pain to the patient, micro molded needles must be designed and manufactured without a blunt tip which would “drag” the skin and cause pain and prolong puncturing. As is the case with any micro technology (thermoplastic, silicone, or metal), the tooling is THE most critical component to success.
The tooling for micro molded needles have features in the double digit micron range, there are several challenges that must be overcome to achieve tool to molded needle replication. It is one thing to make nice sharp corners and cavities in steel (less than 1 micron radii) but it quite another to FILL those tiny spaces with polymer. VENTING, VENTING, VENTING: Similar to the real estate sales mantra “location, location, location” it’s all about proper venting and cavity to core fits for the successful degassing of polymer during the ultra-fast injection phase. Proper venting is required. These tiny pockets of steel in the mold leading to atmosphere allow for the flow of polymer to get right to the bottom of the steel cavity thus creating a very sharp point in polymer.
Mold Insert and Molded Part on left and Micro Molded Needle Sites with <0.050” (1.3mm) tall needles with 0.002” (50 micron) lumens through each site.
Because needles and sharps can be dust speck in size and require micron level radii to achieve skin, tissue, or organ puncture forces, the tooling or micro mold is the true enabler to their success.
Pharma and Drug Delivery Developments Combine
10/8/15 Both micro manufacturing techniques and materials advancements are constantly driving innovation in pharmaceutical devices, combination devices, and drug delivery.
The medical device sector is constantly pushing the drive towards miniaturization. In the medical device industry, the usual advantages of making smaller parts are exacerbated by the requirement for less invasive treatments. In addition, the opportunities for diagnosis and treatment that are available if functioning devices can be swallowed, ingested, or inserted in the body are huge, and constantly stimulate innovation in the micro manufacturing field.
Also, in the area of drug delivery, where the pressure is for treatments to be cost-effectively and efficiently self-administrated (reducing the burden on healthcare practitioners and therefore reducing costs) micro manufacturing is enabling product designers to think out of the box, and makes available to them fabrication technologies that allow for the mass production of parts and devices previously impossible.
Micro manufacturing technologies, materials, and techniques are moving on apace, and today much of the onus on experts in the micro field — such as Micro Engineering Solutions (MES) — is to educate and inform clients of the possibilities, often times reinforcing the fact that many technologies that OEMs perceive as prototyping technologies are now capable of being scaled to mass production quantities.
Applying these capabilities to the dynamic area of drug and device development presents such a huge array of commercial possibilities, but at the same time opens up possible pitfalls for the uninitiated, or those who do not have the expertise to best utilize what is available today, or foresee what is just around the corner. So many recent and imminent device and pharmaceutical developments are being driven by companies that embrace and partner with micro manufacturing experts right at the beginning of the design cycle.
So where does the combination of drug, device, and micro manufacturing development stimulate innovation. Well, broadly speaking, it is fair to say that pharmaceutical companies do and will rely on developments in micro and nano manufacturing for new drug discovery (producing miniaturized products such as microarrays that help in analysis and ingredient synthesis) and reduced drug development time (producing lab-on-a-chip devices that help assess which drug compounds are likely to be most efficacious).
However, once the drug is developed, micro technologies also facilitate new drug delivery options (which can also extend drug lifecycles), and better treatment performance. Many pharmaceutical companies look for ways to extend the lifecycle of their drugs, especially when competing with the burgeoning generics market-place, and one way of doing this is by developing delivery options that are novel, stimulate the possibility of non-invasive drug delivery, increase the efficacy of the drug, and are as small as possible to allow the possibility to be implanted in the body or be easily portable.
Micro molding transdermal patch needles close up
Micro manufacturing technologies have facilitated the possibility for cost-effective mass production of a number of innovative inhaler systems for treatment of asthma and COPD, and have also opened up the possibility of inhaler-based drug delivery devices being used where previously injectables were the only cost-effective option. In many instances, this opens up not only the possibility of self-administration, but also increases drug efficiency, due to the immediacy of drug action when inhaled.
Again, targeting the sometimes cumbersome, costly, and non-patient friendly area of injectables, micro manufacturing has opened up the possibility of drug delivery via micro molded needles arrays and transdermal drug delivery. For a number of years, despite the fact that it was considered potentially the best mechanism to administer insulin, incretin mimetics, and other-protein-based pharmaceutical agents (biologics), microneedle-mediated drug delivery for transdermal delivery was frustrated by the poor performance of the microneedles due to inappropriate available materials and poor fabrication techniques.
Today, micro molding technologies have developed to the point where microneedle structures with appropriate structural, mechanical, and biological properties have opened up a huge number of possibilities for transdermal drug delivery in numerous treatment areas. These micron-sized needles have been shown to dramatically enhance skin permeability, and have opened up the possibility of not just therapeutic drug delivery, but also transcutaeous immunizations and cutaneous gene delivery. The nature of the micro needles is also such that they are minimally invasive and painless, and have numerous safety advantages and patient compliance advantages over traditional injection technologies.
Success in many of the micro manufacturing projects that are applied to medical device and drug delivery development also demand an understanding and working knowledge of some innovative and — in certain instances — difficult to use materials. MES has a proven track record working with degradable polymers such as Polylactide (PLA), Poly-l-lactide (PLLA), Polylactic-co-glycol acid (PLGA), and water soluble Polyvinyl alcohol (PVOH) among others.
In many drug and non-drug related applications, device development is driven not just by advances in micro manufacturing capabilities, but also by the introduction of such innovative degradable, soluble, and bioresorbable polymers. It is now possible to undertake intricate micro molding operations using these and many other innovative materials.
But once again, there are challenges to confront when working with some of these polymers (which are often very expensive). It is vital to understand that many of these materials are both moisture, heat, and shear-sensitive, and the only way to use them economically is to dramatically minimize runner and sprue scrap. The sensitivity to heat and moisture makes them liable to degradation during typical melt processing through compression molding, injection molding, and extrusion. Micro molding has focused on the design of molds and control of processing conditions to overcome these issues, but processing costs are still very high. There are also numerous validation hoops that need to be adhered to, which requires an innate understanding of the regulatory requirements for medical devices, bioresorbables, and cleanroom manufacturing.
Partner selection with all these considerations is obviously critical for medical device OEMs, but the commercial opportunities are huge if device development is optimized. Today, swallowable medical devices exist for diagnosis and surgery (including wireless camera pills), and under development are a range of “micro” swallowable medical devices that can enable advanced diagnostics and even directly deliver surgical tools and therapy non-invasively to interventional sites deep within the GI tract. Also, devices that include electronic components that dissolve in the body are being developed, as are absorbable stents.
The industry is tantalizingly close to being able to address some fundamental issues in healthcare. It will soon be possible, for example, to ensure that all “sharps” used in a medical setting such as needles, scalpels, trocars, and pins are made from resorbable or erodible polymers, meaning that a simple wash cycle would render them harmless.
MES is happy to discuss ways in which its expertise and that of its OEM medical device clients can be combined to develop new and innovative products taking advantages of the huge advances in micro fabrication technologies and new materials.
Please contact Donna Bibber at donna@microengineeringsolutions.com