Come and see innovative solutions for POC diagnostics at the AACC 2010.
Come and visit MiniFAB at the 2010 AACC Clinical Lab Expo in Anaheim California, 27-29 July 2010 to learn more about product development and manufacture of disposable cartridges for diagnostics.
AACC is the largest clinical lab exposition in the world with a target audience of over 20,000 participants expected. Dr. Campitelli will be at the MiniFAB Booth (# 3908) and looks forward to discussing your needs and requirements for developing your next innovative product.
Andrew Campitelli, PHD
Manager Diagnostics
Microfluidics and assay design
The current in-vitro diagnostic (IVD) environment is demanding faster, more robust assays which can be performed in decentralised settings by minimally trained users at low-cost. This has led to a whole new field of miniaturisation, with the aim of smart diagnostic cartridges that can perform complex protocols. There are a number of objectives when miniaturising assays:
- Financial – reducing the costs of materials and manufacturing process,
- Ease of use – simplification of sample preparation, analysis and result presentation,
- Mobility – utilisation in point-of-care situations,
- Complexity – multiple analyte testing with each sample received
- Automation – eliminating inherent risk of manual pipetting steps
As the term suggests, microfluidics deals with the behaviour, precise control and manipulation of fluids that are geometrically constrained to a small scale. Depending on the user requirements microfluidics can be designed deliver a large number of diagnostic relevant outputs, such as electrochemical applications, immunoassays and polymerase chain reactions (PCR). There are a number of fundamental differences between tube based assays and microfluidic assays which are important to consider during assay design. Viscosity and surface tension play an important role when mobilising complex reagents through narrow channels. The small volumes utilised in microfluidic assays becomes significant when analysing low concentration samples.
A reduced reaction volume may positively affect the kinetics of the assay because reagents come into contact with each other at higher rates in reduced volumes, thereby reducing the time required for the reaction to reach equilibrium. However, as the sample size is reduced, the number of molecules in the sample decreases which restricts the scale and sensitivity of assays. Non-specific binding of samples and reagents can be more problematic due to higher surface-volume ratios than in a tube. Use of low-binding materials and use of surface blocking agents become critical to maintaining sensitivities. In order to effectively translate tube based assays to a microfluidic cartridge it is critical that the individual inputs (sample), outputs (e.g. nucleic acids from extraction or PCR, NASBA), and process conditions (e.g. temperature, concentrations, pH) of often discontinuous bench top assay steps are fully understood.
Translating individual assay steps to microfluidic cartridges allows benchmarking against industry standard tubes based approaches.
Only after the required sensitivities and specificities are demonstrated on individual cartridges should an integrated prototype be developed that performs all steps from sample collection and preparation, mixing of reagents, reaction, incubation, and detection.
MiniFAB works with its client to split your assay steps into microfluidic toolbox diagrams capturing each discrete assay step and then develop proof-of-principle cartridges for each step. Cartridge designs aim to leverage the existing fluidic control available on MiniFABs MiniChemlab workstation avoiding costly development of instrument test beds, adding heating, electronic, or optical modules as required by the assay. Automated delivery of samples and reagents to the cartridge allow for robust and repeatable assay development.
John McCormack
Project Manager
Product Innovation Assessment
The integration of micro, nano and bio technologies offer exciting potential for product development but besides the technical hurdles there are obvious business risks involved in embracing technology-based products as key growth strategies. MiniFAB has a proven strategy for engaging clients at an early stage in the Product Development cycle by offering a Product Innovation Assessment process. This enables clients to conduct an inexpensive assessment and fine-tuning process before committing to a full scale product development phase.
The product innovation/assessment phase is a circular process with no prescribed number of iterations. Short work packages are defined and aimed at reducing the identified business and technical risks. This process minimises and limits the financial exposure in the early stages of product development. At the end of a cycle, outcomes are reviewed and the next round of investment is sought and committed. The process is conducted until risk is deemed to have decreased to a level where investors are comfortable to commit to the product development phase, which typically costs at least an order of magnitude higher than the innovation assessment phase.
The order of steps is not prescribed. Generally, initial work is focused on the steps which carry the biggest risk. Activities in this phase are not necessarily conducted within strict rules of applicable standards but instead in a manner that gives a sufficient level of confidence that a successful conclusion can be reached. The processes can then be validated and accepted within the context of the product development program.
From MiniFAB's perspective the process allows for flexibility, particularly the ability to plan and price small individual steps that can fit within a client's budget and produce a quick result. In addition, completion of product assessment work packages often require less long-term planning compared with Product Development and Manufacturing programs as the latter require a higher level of program definition as they often need to follow strict rules prescribed by relevant standards and regulatory authoritries.
The ideal result at the end of the Product Innovation Assessment phase is a smooth progression to product development and then to product manufacture. MiniFAB manages the entire scope of this program for its clients. We would encourage you to enage with MiniFAB at an early stage in the product development cycle and take advantage of the assessment program aimed at mitigating project risk. This is likely to be the most time and cost effective way develop your product.
Dusan Milojevic
Devices Manager
Lithography for Microfabrication
Lithography is a versitile tool for patterning fine microstructures and has been widely used for many years in the manufacture of silicon based MEMS devices and micro-electronic components. The processes are well established for volume manufacture and are used to make products that are relied upon in everyday life. To make these products cost effectively, a high throughput is required to offset the high capital cost involved in these processes. This can create a barrier for early stage development projects that find it difficult to access such facilities.
In addition to cost barriers, design flexibility and speed of response are also common barriers for early stage development projects accessing such foundry services. These types of projects generally seek to fabricate small quantities of devices for proof-of-principle testing and validation. In order to achieve this, there is often an undesirable comprimise between design and response time in order to bring costs to a managable level. A method commonly used to do this is to share space with other projects on a common substrate, which may not be suitable for some projects.
MiniFAB operates a specialized suite of UV-lithography equipment that is ideally suited for such early stage development projects. When used in conjunction with our electroforming and metal deposition techniques, MiniFAB offers a cost-effective process to fabricate small batches of devices for testing and validation. In addition, MiniFAB's wirebonding service can be used at the end of this process to integrate the fabricated test device to an electronics board for laboratory testing. This process provides the researcher a dedicated development process for the fabrication of proof-of-concept devices. The quick response of the process cylce allows for design modifications at each iteration if required.
MiniFAB's lithography capability is not limited to silicon based MEMS devices but can be used in several innovative ways to fabricate the desired microfeatures within a product. We offer access to common photoresists, spinnable or dryfilm, positive or negative, ranging in thickness from 1-200 um. The process capabilities of lithography can be exploited to pattern fine microstructures on polymers or specialty substrates which can be integrated within a microdevice when combined with MiniFAB's direct microfabrication capabilities such as laser micromachining or micromilling. For example, UV-lithography can be used to pattern micro-channels in materials that can be subsequently laser patterned.
We encourage you to engage MiniFAB in the early stage of your product development cycle to help determine the best fabrication routes and to fabricate provide proof-of-principle devices for testing and evaluation.Rick Barber
Jobshop Manager