We have a winner!
The inventors have picked Noise cancelling Exhaust Pipe / muffler / silencer by Ian Downie
as their winner for this competition. Here's what they had to say about Ian's idea:
"This is an extremely novel idea. Ian has truly grasped the important aspects of our material, and his suggested application is ideally suited. This is not something we had considered, is feasible, has a large market, with great potential. In addition, the description Ian has put together, with use of diagrams is extremely elaborate. Thanks a lot!"
The bottom line
: While all of this piezoelectric material's properties are competitive with (or superior to) the current gold standard, its most unique property is its high temperature resistance
. The key to a successful entry is to find a large-enough market
in which this property specifically would provide a competitive advantage. More about this in the "Your mission" section.
Piezoelectricity refers to the phenomenon of electric charge building up in certain solid materials in response to applied mechanical stress; and vice versa, a shape change can be generated via an applied electric field. Now as a crew of British materials scientist we’ve successfully created the next big thing in piezoelectrics: a material that’s dirt cheap (as cheap as the current market-leader PZT), but which is several-fold more powerful and able to be used at high temperatures and high stresses. And we’re hoping you could find a way to take advantage of these new features by building commercial cases around which new products we could create from it.
Piezoelectric materials are generally ceramics, which are able to (a) change shape when a voltage is applied to them or (b) generate an electrical signal when a force is applied.
As actuators, sensors and transducers (a combination of the former two) they are the irreplaceable heart of systems such as medical ultrasound imaging, vibrational energy harvesting and SONAR comprising a $15bn annual market dominated by one material – PZT. However, application areas are limited because PZT’s properties rapidly degrade above 200°C (or even before, if high stresses are simultaneously applied). That’s where we come in, with a material called HPZ. The physics behind it and the way that it is made is near identical to PZT, but through some clever materials engineering we raised the maximum operating temperature above 350°C
(Marblar warning: that’s hot). What’s more:
- We can achieve a shape change that’s double that of any other piezoelectric (apart from single crystals, which are fragile and hugely expensive, so who care’s about them?)
- It’s extremely robust
- The cost (at scale) is the same as PZT.
- We can optimize the material for high activity (the materials property relating electric field and deformation) or high operating temperature (and any intermediate configuration) by simply altering the mixture – with PZT you need to add extra elements to do this.
What we need from you are some (not too niche) markets for our HPZ that aren’t currently dominated by PZT
– i.e. sensor/actuator applications that are only really made possible by our high-performance, high-temperature material or where non-piezo technologies are currently used.
We’ve commercially developed the material for various high temperature applications involving dynamic pressure, acoustic, or ultrasound sensors. There are quite a few other high-temperature applications we’ve considered, but not delved into in much detail, which should give you some ideas where to start looking:
- Non-destructive ultrasonic testing (NDT) in nuclear, chemical, or process plants
- Printing (e.g. molten plastics, metal)
- Valves and actuators – done presently by PZT/magnetic systems (cooled, or at “arms length”, which increases complexity, decreases performance).
- Automotive and aerospace fuel injection – Not done in aero, current technology for auto uses PZT, but at the ragged edge of performance.
- Plethora of high-temperature / high-pressure oil and gas applications, incl. NDT, communications, valves. However, PZT is unsuitable for deep, hot oil fields.
- Energy harvesting (vibration) and accelerometers (shocks) – transport, industry.
- Morphing structures for e.g. supersonic aircraft without external moving parts. PZT and shape memory alloys currently used in prototypes.
We are looking for sizeable application markets (not too niche!) where we can use the specific advantages of our piezoelectric material (usable at higher temperatures, less brittle, more work output) and have a clear competitive advantage compared to the existing technologies used.
We do NOT want to compete head-to-head with existing PZT markets just yet. We need to find the new markets and/or markets where we can replace other non-piezo sensing/transducing/actuating technologies with piezos.
We’re looking for both specific business cases in the general areas described above and completely new applications – with info in each case on:
- What specific properties should we tailor our material to?
- What else needs to be considered (e.g. high-temperature electrical connections)?
- Who would be relevant partners in that specific sector?
Comparing HPZ directly to PZT, which dominates the piezoelectric market:
Can tune high temperature resistance and high activity by modifying the architecture of the material.
- Roughly double the strength
- Roughly the same precursor materials, production/post-processing and underlying physics: cheap, easy adoption, reliability
- Low lead content – 15-25% vs. 65% for PZT
- Change in shape double that of any previous material (excluding single crystals), work output (strain times stiffness) more than 5x that possible with PZT
Properties lie on the curve shown below with comparisons to competing materials.
- Very high temperature materials (BLSF, PLS) generally have extremely low activity.
- BSPT can have both higher activity and temperature resistance than our material, but is extremely expensive. Also, as we can apply higher electric fields to HPZ, we can achieve greater total deformation.
- Single crystals (other discussed materials are made up of millions of small crystallites) can have extremely high activity – but at 1000x cost and low strength and temperature resistance.
We (Andrew Bell, Tim Comyn and Tim Stevenson) have been working with piezoelectric ceramics for a combined 40 years. Over the last decade we started working on high temperature systems, in collaboration with the aerospace sector. We have spent much of this time developing new materials and fine-tuning, rooted in a fundamental understanding of the underlying materials science and physics. In the last couple of years we realised that we had developed something truly unique, an enabling technology, with a plethora of potential commercial applications. As much as we love the scientific behind these materials, seeing them being used in real world applications is the ultimate test – and that’s why we’re excited for your input!
WO 2012013956 A1, Authors Comyn, Bell, University of Leeds
J. Bennett, A.J. Bell, T.J. Stevenson, T.P. Comyn , “Exceptionally large piezoelectric strains in BiFeO3–(K0.5Bi0.5)TiO3–PbTiO3 ceramics
” Scripta Materialia, 68(7), 491-494, 2012.