Category Archives: design

Happy New Year!

Decorative photograph of sculpture of a skeletal person leading a skeletal dinosaurThis year I have written about 20,000 words in 52 posts (including this one); and, since this is the last post of the year, I thought I would take a brief look back at what has preoccupied me in 2021.  Perhaps, not surprisingly the impact of the coronavirus on our lifestyle has featured regularly – almost every week for a month between mid-March and mid-April when we were in lockdown in the UK.  However, the other topics that I have written about frequently are my research on the dynamics of nanoparticles and, in the last six months, on dealing with uncertainty in digital engineering and decision making.  I have also returned several times to innovation processes and transitioning lab-based research into industry.  While following the COP26 in early November, I wrote a series of three posts focussed on energy consumption and the paradigm shifts required to slow down climate change.  There are some connections between these topics: viruses are nanoparticles whose transport and dynamics we do not fully understand; and, digital engineering tools are being used to explore zero-carbon approaches to, for example, energy generation and air transport.  The level of complexity, innovation and urgency associated with developing solutions to these challenges mean that there are always some unknowns and uncertainty when making associated decisions.

The links below are grouped by the topics mentioned above.  I expect there will be more on all of these topics in 2022; however, the topic of next week’s post is unknown because I have not written any posts in advance.  I hope that the uncertainty about the topic of the next post will keep you reading in 2022! 

Coronavirus pandemic: ‘Distancing ourselves from each other‘ on January 13th, 2021; ‘On the impact of writing on well-being‘ on March 3rd, 2021; ‘Collegiality as a defence against pandemic burnout‘ on March 24th, 2021; ‘It’s tiring looking at yourself‘ on March 31st, 2021; ‘Switching off and walking in circles‘ on April 7th, 2021; ‘An upside to lockdown‘ on April 14th, 2021; ‘A brief respite in a long campaign to overcome coronavirus‘ on June 23rd, 2021; and ‘It is hard to remain positive‘ November 3rd 2021.

Energy and climate change: ‘When you invent the ship, you invent the shipwreck‘ on August 25th, 2021; ‘It is hard to remain positive‘ November 3rd 2021; ‘Where we are and what we have‘ on November 24th, 2021; ‘Disruptive change required to avoid existential threats‘ on December 1st, 2021; and ‘Bringing an end to thermodynamic whoopee‘ on December 8th, 2021.

Innovation processes: ‘Slowly crossing the valley of death‘ on January 27th, 2021; ‘Out of the valley of death into a hype cycle?‘ on February 24th, 2021; ‘Innovative design too far ahead of the market?‘ on May 5th, 2021 and ‘Jigsaw puzzling without a picture‘ on October 27th, 2021.

Nanoparticles: ‘Going against the flow‘ on February 3rd, 2021; ‘Seeing things with nanoparticles‘ on March 10th, 2021; and ‘Nano biomechanical engineering of agent delivery to cells‘ on December 15th, 2021.

Uncertainty: ‘Certainty is unattainable and near-certainty is unaffordable‘ on May 12th, 2021; ‘Neat earth objects make tomorrow a little less than certain‘ on May 26th, 2021; ‘Negative capability and optimal ambiguity‘ on July 7th, 2021; ‘Deep uncertainty and meta ignorance‘ on July 21st, 2021; ‘Somethings will always be unknown‘ on August 18th, 2021; ‘Jigsaw puzzling without a picture‘ on October 27th, 2021; and, ‘Do you know RIO?‘ on November 17th, 2021.

Follow your gut

Decorative image of a fruit fly nervous system Albert Cardona HHMI Janelia Research Campus Welcome Image Awards 2015Data centres worldwide consume about 1% of global electricity generation, that’s 200-250 TWh (Masenet et al, 2020), and if you add in mining of cryptocurrencies then consumption jumps by about 50% (Gallersdörfer et al, 2020). Data transmission consumes about 260-340 TWh or at least another 1% of global energy consumption (IEA, 2020).  The energy efficiency of modern computers has been improving; however, their consumption is still many millions times greater than the theoretical limit defined by Landauer’s principle which was verified in 2012 by Bérut et al.  According to Landauer’s principle, a computer operating at room temperature would only need 3 zJ (300 billion billionths of a Joule) to erase a bit of information.  The quantity of energy used by modern computers is many millions times the Landauer limit.  Of course, progress is being made almost continuously, for example a team at EPFL in Lausanne and ETH Zurich recently described a new technology that uses only a tenth of the energy of current transistors (Oliva et al 2020).  Perhaps we need turn to biomimetics because Escherichia Coli, which are bacteria that live in our gut and have to process information to reproduce, have been found to use ten thousand times less energy to process a bit of information than the average human-built device for processing information (Zhirnov & Cavin, 2013).  So, E.coli are still some way from the Landauer limit but demonstrate that there is considerable potential for improvement in engineered devices.


Bérut A, Arakelyan A, Petrosyan A, Ciliberto S, Dillenschneider R & Lutz E. Experimental verification of Landauer’s principle linking information and thermodynamics. Nature, 483: 187–189, 2012.

IEA (2021), Data Centres and Data Transmission Networks, IEA, Paris

Gallersdörfer U, Klaaßen L, Stoll C. Energy consumption of cryptocurrencies beyond bitcoin. Joule. 4(9):1843-6, 2020.

Masanet E, Shehabi A, Lei N, Smith S, Koomey J. Recalibrating global data center energy-use estimates. Science. 367(6481):984-6, 2020.

Oliva N, Backman J, Capua L, Cavalieri M, Luisier M, Ionescu AM. WSe 2/SnSe 2 vdW heterojunction Tunnel FET with subthermionic characteristic and MOSFET co-integrated on same WSe 2 flake. npj 2D Materials and Applications. 4(1):1-8, 2020.

Zhirnov VV, Cavin RK. Future microsystems for information processing: limits and lessons from the living systems. IEEE Journal of the Electron Devices Society. 1(2):29-47, 2013.

Digital twins that thrive in the real-world

Decorative image

Windows of the Soul II [3D video art installation:

Digital twins are becoming ubiquitous in many areas of engineering [see ‘Can you trust your digital twin?‘ on November 23rd, 2016].  Although at the same time, the terminology is becoming blurred as digital shadows and digital models are treated as if they are synonymous with digital twins.  A digital model is a digitised replica of physical entity which lacks any automatic data exchange between the entity and its replica.  A digital shadow is the digital representation of a physical object with a one-way flow of information from the object to its representation.  But a digital twin is a functional representation with a live feedback loop to its counterpart in the real-world.  The feedback loop is based on a continuous update to the digital twin about the condition and performance of the physical entity based on data from sensors and on analysis from the digital twin about the performance of the physical entity.  This enables a digital twin to provide a service to many stakeholders.  For example, the users of a digital twin of an aircraft engine could include the manufacturer, the operator, the maintenance providers and the insurers.  These capabilities imply digital twins are themselves becoming products which exist in a digital context that might connect many digital products thus forming an integrated digital environment.  I wrote about integrated digital environments when they were a concept and the primary challenges were technical in nature [see ‘Enabling or disruptive technology for nuclear engineering?‘ on January 28th, 2015].  Many of these technical challenges have been resolved and the next set of challenges are economic and commercial ones associated with launching digital twins into global markets that lack adequate understanding, legislation, security, regulation or governance for digital products.  In collaboration with my colleagues at the Virtual Engineering Centre, we have recently published a white paper, entitled ‘Transforming digital twins into digital products that thrive in the real world‘ that reviews these issues and identifies the need to establish digital contexts that embrace the social, economic and technical requirements for the appropriate use of digital twins [see ‘Digital twins could put at risk what it means to be human‘ on November 18th, 2020].

Hot air is good for balloons but cold air is better for cars

photograph of a MDI Airpod 2.0Cars that run on air might seem like a fairy tale or an April Fools story; but it is possible to use air as a medium for storing energy by compressing it or liquifying it at -196°C.  The MDI company in Luxembourg has been developing and building a compressed air engine which powers a small car, or Airpod 2.0 and a new industrial vehicle, the Air‘Volution.  When the compressed air is allowed to expand, the energy stored in it is released and can be used to power the vehicle.  The Airpod 2.0 weighs only 350 kg, has seats for two people, 400 litres of luggage space and an urban cycle range of 100 to 120 km at a top speed of 80 km/h.  So, it is an urban runabout with zero emissions and no requirement for lithium, nickel or cobalt for batteries but a limited range.  A couple of years ago I tasked an MSc student with a project to consider the practicalities of a car running on liquid air, based on the premise that it should be possible to store a higher density of energy in liquified air (about 290 kJ/litre) than in compressed air (about 100 kJ/litre).  His concept design used a rolling piston engine to power a family car capable of carrying 5 passengers and 346 litres of luggage over a 160 km.  So, his design carried a bigger payload for further than the Airpod 2.0; however, like the electric charging system described a few weeks ago [see ‘Innovative design too far ahead of the market’ on May 5th, 2021], the design never the left the drawing board.