PECM Issue 50 2021 | Page 56

ELECTRICAL & ELECTRONICS

Accurate , precise dispensing for wearable technology

When manufacturing a medical device , it is important that all processes are reliable , consistent and can be validated . The industry requires manufacturers to have a good understanding of process variables , and to control them to create a robust procedure across all dispensing processes . Dispensing processes must be done accurately and repeatably .
DISPENSING IN ACTION To achieve the level of precision required , manufacturers can opt for progressive pump technology , as it enables true volumetric dispensing . A progressive cavity pump typically consists of a single-helix metal rotor and a double-helix hole in an elastomeric stator , which forms a sequence of small discrete cavities . These cavities progress through the pump as the rotor is turned , transferring the liquid . The output represents true volumetric dispensing — the amount of material is directly proportional to the number of rotations of the rotor , and is not affected by material viscosity , input pressure or ambient temperature .
One example technology is the eco-PEN330 preeflow dispenser , which enables the user to dispense volumes as small as 0.001 µ l within 1 %, 99 % of the time — a high level of repeatability and accuracy . It can be used for low or high viscosity materials , with or without filler content .
DISPENSING FOR DIABETES MANAGEMENT Medical wearable devices have huge potential for diabetes management . For example , in the US , the digital diabetes management market size has a compound annual growth rate of around 20 %. Examples of technologies include continuous glucose monitoring , smart glucose metres and closed loop systems .
One interesting example comes from a client of ViscoTec India , whose engineers created a closed loop system , consisting of a skin patch that measures blood glucose levels , a device that calculates the required insulin dose , and a smart pump that injects the dose . During the production process , the manufacturer required the precise dispensing of 0.7 microlitres of grease into a gearbox component of the electric motor in the insulin pump . These precise requirements were fulfilled with a preeflow eco-PEN330 .
AUTOMATING THE PROCESS In most wearable production processes , adhesive dispensing is automated to achieve a high degree of repeatability . Once the dispensing technology has been selected , manufacturers can repeat the application of materials with positional accuracy by incorporating a robot or other form of automation . Medical device manufacturers have several options to mechanise the process , which include rotary tables or simple 3-axis benchtop robots , usually at modest cost , right up to multi-axis robots with vision-based control and feedback
As well as delivering productivity benefits from their speed , consistency and ability to run continuously , automation can enable results not possible manually . They can deliver rapid return on investment , particularly when precision and accuracy-based productivity gains are taken into consideration .
For more information , visit www . intertronics . co . uk /

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+ 44 ( 0 ) 1925 811 290 / sales @ tempapano . co . uk / www . tempapano . com
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