FLEX FANS

Industry Issues
Air cooling is still the most commonly used thermal management approach for electronics.  In some cases the commercial viability of important energy-related technologies, such as LED lighting products, depends on 10 years of fan life while conventional fans only provide 3 years. Other applications such as sealed military or telecom electronics enclosures need internal air cooling but limited fan life prevents it.  Fan bearings are the source of fan failure and the very hot environments where fans are most needed will evaporate bearing lubricants and dramatically shorten their 3 year life.

Influent’s Flex Fan Solution
The introduction of flex fan technology opens the door to 10 year fan life for air cooled electronics products. Influent’s flex fans are designed to provide the form factor, enabling life, near silent operation and target price points required for commodity thermal management applications such as HBLED lighting products. Despite the commodity price points, flex fans are inherently suited to provide long life in extreme/harsh environments such as in military and telecom applications.

Unlike rotary fans, the blades of a flex-fan do not rotate. Instead they bend or flex. The blades bend in a cantilever mode, being clamped on one end with the other end free to oscillate. The oscillation of the blade’s free end moves air in a similar way to the blades of a rotary fan. 

Flex fans are electromagnetically-driven; powered by simple and inexpensive drive circuits; provide quiet low frequency operation (e.g. 30 Hz) and provide form factors small enough to fit inside an A-sized LED lamp.  Flex fans can provide either axial or radial air flow and can be scaled for a range of end product sizes, from PDAs to commercial lighting applications.

Past industry efforts to commercialize cantilever fan technology failed due to the use of expensive piezo technology, noise and vibration issues, excessive size and unwieldy form factors.

Application Example
Influent developed a flex fan solution for an LED lighting customer that enabled a 1,600 lumen light output in an A-sized LED lamp while maintaining junction temperatures 15°C below that required for 10 year life.  Delivered performance is summarized in the following table.

PULSED AIR JETS

Industry Issues
High power products like servers are prevented from providing much higher computing performance due to the current limits fan technology. Simply driving more air end-to-end through a product is not viable from an energy standpoint since fan power increases with the cube of the fan’s flow rate.  Also, increased fan flow requires higher fan speeds which result in unacceptable noise levels and reduced fan life.  As such, thermal management is often the gating issue for achieving higher computing performance.  These issues have led to an industry concern that air is reaching its practical limits as the prime thermal management solution for cooling servers and other high power electronics products.  Further, fan failure rate is a significant issue and the need for extended fan life without increased fan cost remains unmet.

Influent’s Air Jet Solutions
Using its breakthrough drive platforms, Influent has designed a new family of air jet actuators that significantly increase air cooling performance while reducing size and cost.  These air cooling systems extend the performance horizon of air cooling in electronics products and also in applications that were previously out of reach due to internal product space constraints or limited fan life concerns.

Influent’s high power density drive systems enable a single jet actuator to drive a large manifold with an array of ports that deliver high velocity air jets to hot spots spread over large product platforms. The combination of thin manifolds and Influent’s small powerful actuators provides a low-profile low-energy-loss air distribution system within space constrained products. Referred to as “proportional air delivery” this approach provides air only where it’s needed instead of pushing high velocity air through the entire platform.  Resulting fan load reductions can reduce system fan power by as much as 80%.

Application Examples

For an example of how Influent’s synthetic jet systems can solve high power thermal challenges, see the white paper “Reducing Server Power Consumption by 20% With Pulsed Air Jet Cooling.”

Influent’s jet actuators can be scaled to cover a wide range of product sizes from high power density systems like servers to cooling HBLED lamps. The photo shows a high power jet actuator for server applications and a smaller jet actuator for LED lamp cooling applications.  The LED lamp actuator was developed for a LED lighting customer and enabled a 1,600 lumen light output in an A-sized LED lamp while maintaining junction temperatures 15°C below that required for 10 year life (performance similar to that shown in the flex fan LED performance table).  Other applications include sealed military and telecom enclosures and general thermal management needs.

MINIATURE COMPRESSORS & PUMPS

Industry Issues
A growing number of medical, electronics, military and consumer products require small liquid pumps and compressors that provide higher fluid performance in a much smaller form factor and at significantly lower price points. These requirements are out of reach for conventional miniature compressors and pumps due primarily to the large expensive rotary motors that power them.  Rotary motors and the related drive linkage used in conventional devices comprise at least 50% of the pump/compressor size and 80% of the cost.

Influent’s Solution
Influent’s integrated drive systems, replace the large conventional rotary motors with small actuators that are closely integrated with the fluid components, resulting in significant miniaturization and much higher pumping power densities.  These drive systems are only a fraction of the cost of rotary motors, thereby enabling significant reductions in miniature pump/compressor cost.  An absence of frictional components allows Influent’s fluid mover products to satisfy ever increasing life requirements.  Influent’s fluid mover products can provide a variety of new form factors enabling them to fit in places where conventional devices cannot.

The result is a new generation of miniature compressors, vacuum pumps and liquid pumps with the performance, size, cost and life to enable today’s new tech products and applications.

Applications
Influent’s new miniature compressors, vacuum pumps and liquid pumps meet application requirements in O2 concentrators, ambulatory medical devices, liquid cooling loops using single and two-phase liquids for thermal management, micro fuel cells, air and liquid sampling, military and consumer products such as non-propellant sprayers and general purpose pump and compressor applications.

PUMP & COMPRESSOR PRODUCT EXAMPLES
Influent’s numerical models provide accurate performance forecasting for a wide variety of applications. Modeled performance is typically within 10% of actual hardware performance. The following product examples show high-confidence modeled data for proven drive system platforms.

1. Air Compressors for O2 Concentrators

The following table shows the forecasted performance for an Influent air compressor sized for a 2.5 liter O2 concentrator.  Results are bench marked against a Thomas 230 series compressor which is also sized for the same product. The Influent compressor shows a 50% reduction in actual compressor volume and more than a 75% decrease in mechanical outline volume (mechanical outline volume may be more indicative of the form factor space a compressor occupies in the end product).  Weight is reduced by 38% and power consumption by approximately 23%.  Reductions in compressor manufactured cost could be as much as 75% due to Influent’s low cost drive platform that eliminates expensive rotary motors. Profile views of the Influent and Thomas
compressors are shown below the table to illustrate the difference in form factors.

2. Air Compressors for Micro fuel Cells

The following table shows the forecasted performance for an Influent air compressor sized for a small micro fuel cell battery charger.  Results are bench marked against a KNF compressor that is also sized for the same application. The Influent compressor shows a 50% reduction in actual compressor volume, a 40% decrease in mechanical outline volume (mechanical outline volume may be more indicative of the form factor space a compressor occupies in the end product) and a 23% decrease in power consumption.  The high prices of conventional miniature compressors would prevent large scale market adoption of micro fuel cell chargers. The Influent compressor meets the price targets and provides price reductions of up to 75% due to Influent’s low cost drive platform that eliminates expensive rotary motors. Side-by-side views of the Influent and KNF compressors are shown below the table at relative scale.

___________

3. Liquid Pumps for Laptop Cooling

Influent was approached to design a liquid pump for a high performance laptop using a single-phase liquid cooling loop. The resulting modeled performance is compared with other commercially available pumps in the table below.  Single-phase liquid cooling loops require high liquid flow rates. For a two-phase liquid loop the liquid flow rates and the pump size would be much smaller. The designed pump’s dimensions are 50x50x12mm and its operating frequency is 100Hz.

For miniature pump applications one of the most important metrics is pumping power density, defined as pumping power divided by the pump size (i.e. pump volume).  The table shows how the Influent design compares with other commercially available products on pumping power density and power consumption. For these comparisons, one pump product was chosen from each of the leading manufacturers, representing the smallest product offered that can deliver at least a minimum of 1 L/min at 5 psig outlet pressure. These products represent the smallest commercially available pumps on the market for the target performance of 1-2 L/min at 5 psi.

©2011 Influent Corp.