Imagine that there exists a two-dimensional (single-layer) crystal that is made of a commonly available element, is stronger than steel yet lighter weight and flexible, displays ballistic electron mobility (for comparison, two orders of magnitude greater mobility than silicon, at room temperature), and is sufficiently optically active to see with the naked eye (though far more practically, using an optical microscope). Prospective applications include flexible, high-speed electronic devices and new composite materials for aircraft.
Would this sound like a potentially world-changing substance worthy of scientific attention and funding?
That substance is graphene, a single layer of graphite with hexagonally arranged carbon atoms (visualized as chicken wire).
Now imagine that the mechanical properties of this substance aren’t measured yet, as was the case for graphene before 2009. Imagine further that there is no way to grow or isolate the single-layer crystals in their free state, as was the case for graphene before 2004. Stepping back in time yet further, imagine that the theoretical work predicting massless charge carrier behavior hasn’t been carried out yet, as was the case for graphene before 1984.
Peeling back these milestones, we can see that if the scientific question being asked is “What can be realized from here?” then the graphene timeline played out characteristically, with major advancements coming primarily from opportunity-based research. In other words, over 50+ years, from the initial theoretical work on graphene in 1947 until stable monolayers were achieved in 2004, there was limited vision of what end-goals might be achievable and limited drive to get there.
What happens when a different question is asked, specifically “What can be realized according to physical law?” This is the key premise of the exploratory engineering approach, a methodology proposed by Eric Drexler for assessing the capabilities of future technologies. He points out, for example, that the principles of space flight had been worked out long before science and industry advanced enough to get to actual launch.
For initial space flight development, the answers to the two questions above were dramatically different: what could be done in practice was far behind what had been established as theoretically possible, and there was no defined path between them. By identifying what was achievable according to physical law, the longer-term goal of space flight entered the consciousness of physicists, engineers, and politicians, bringing great minds and great resources to the challenge.
With the benefit of similarly future-focused knowledge, perhaps graphene might have received far more attention far sooner. Consider this: the groundbreaking experimental work that sparked the field as we know it today was the discovery that single-layer graphene could be extracted from a piece of graphite by (essentially) pressing cellophane tape against it and peeling it away. In other words, a decades-long roadblock to achievements in graphene research was not a matter of inadequate supporting technology but one of limited scientific attention.
Here graphene serves as a useful illustration of how progress could potentially be hindered when opportunity-based research is relied upon exclusively. Scientific advancement could benefit significantly from deliberate, exploratory engineering. Perhaps there are numerous other ‘graphenes’ right now, going unnoticed or under-prioritized, because we are failing to ask: what can be realized according to physical law?
-Posted by Stephanie C
