#371: Rainbow drinks

Drinking a tumbler full of cocktail or smoothie can become a chore by the end -you can adapt pretty quickly to one taste so that it becomes cloying…wouldn’t it be great if drinks had an element of surprise?

Today’s invention is a way to liven drinks up.


A honeycomb material could be supplied to bars. It would be closed on one side, open on the other (forming vertical tubes, each wider than a drinking straw).

When a multicomponent drink is ordered, a section of this material could be cut off and inserted into the right size of glass.

The measures required to make the drink would be poured in, as usual, but distributed non-uniformly by hand across the tubes.

A straw would be used to drain each tube in turn -each of which would contain a different combination of components -providing a much more exciting tipple.

Each tube would contain a different coloured mixture as well -making for a more interesting visual experience too.

#370: Spoke springs

I once had a Yamaha motorcycle with wheel spokes which were curved (made of cast aluminium alloy). There was much tutting at the time, in the technical press, that this was an example of form over function.

In view of the fact that lots of today’s bicycles have several springs, swingarms and dampers embedded in their frames, why not just simplify things and use spokes which are inherently springy? Most conventional thinking about spokes says that they should be as rigid as possible; stiffening the wheel to ensure effective ‘feedback’ from the road surface (and limiting fatigue damage).


But what if you want to be transported on a featherbed and don’t much care about performance? As long as the spokes are stiff in the wheel axle direction, they can stand to be pretty flexible radially. This would probably mean that the hub of the wheel remains slightly eccentric when in motion, but to anyone who has tried to ride over cobbles, springy spokes have got some obvious advantages.

I’d suggest making the spokes C-shaped in the plane of the wheel (allowing alternating tension and compression) and with an oval section with its long axis parallel to the wheel axle (to ensure the rim stays coplanar with the hub).

#369: ImPrompTu

As teams of people increasingly work in distributed locations, it’s becoming harder to coordinate face to face activities.

Even organising a brief team-building lunch in advance can turn into a planning task more akin to hosting a UN convention.


Lots of software exists to arrange meetings by specifying the possible dates and then maximising the number of participants available on the day. Today’s invention is a program which hunts for impromptu opportunities (at less than a day’s notice).

It constantly searches a shared online calendar system for spaces in which every member of a small team is ‘free’ and, subject to a set maximum frequency for such events, proposes a shared coffee or lunch break to all concerned.

This can be used to provide people with a source of pleasant surprises at work (as opposed to the drudgery of formal meeting arrangements).

#368: Top5

If anyone were remotely interested, one of my top five films is High Fidelity.

Today’s invention springs from the idea in the original book that everyone likes to describe themselves in terms of their likes and dislikes.


When you meet someone new, you text them a unique codeword which they can choose to forward to a central public number. This downloads to their mobile device a list of say your top five movies, music recordings and books. They can then select any of these to receive immediately a clip or quotation from each.

Naturally, this service would cost the person whose favourites were being viewed. It might also allow an occasional advert to be interspersed in order to lessen the cost of payments to the copyright holders.

#367: Aeropants

Racing cyclists have resting heartbeats of 32, shave their entire bodies and dress in skintight lycra. These characteristics alone would mark them out as ‘different’ but they are, as a breed, also uniquely fetishistic about their kit. You can pay £700 for a pair of turboflex graphite composite aero blades…without having a clue about why they can cut your triathlon time by 0.0001 sec…you just have to buy them.

Today’s invention is for all those obsessives to whom such cycling minutiae matter.


Given that aerodynamic forces are highly significant, I suggest that one of the most obvious sources of drag are the legs of the rider thrashing up and down. If you don’t want to encase him in a monocoque, then you have to live with that…well, no.

Each leg of the cyclist’s skintight outfit would be equipped with four, tubular air bladders (one for the front and back of the upper and the lower leg). Each of these would lie flat when deflated and when inflated, take up a triangular cross-section -like the trailing edge of an aerofoil.

As the cyclist presses down on the pedal, (ie leg moving backwards relative to the air) some of his effort is used to pump up the bladders on the front of his leg, providing it with a temporary, low form drag configuration. When the foot pressure is released (leg moving forward), the air is transferred to the bladders on the rear of the leg.

This can be accommodated within a standard flexible suit and would also provide an illusion of enhanced muscularity.

#366: Knifelock

It scares me to see people using penknives for cutting anything other than flimsy quill feathers.

Even the Swiss army must regularly slice their fingers because folding knives usually don’t lock.


Today’s invention is a spring steel clip designed to grip a penknife blade and prevent it from folding closed when in use.

#365: Shelf-awareness

365 daysToday is the first anniversary of IOTD. I’d like to say thanks to all my readers, especially those who have left comments. Keep watching this space!

For people who still can’t resist the lure of buying books, being able to find the one you want, within a bulging bookcase, can be a daunting task. Even if you can be bothered to sort the damn things alphabetically, every birthday or booksale means another cartload of titles has to be added in the right positions. I’d rather spend the time reading the contents than searching the spines.

Today’s invention is a way to find the book you want, without having to do any manual shelf sorting.


Almost every book now published has a barcode printed on the back. Each time a new book is bought (or a read one replaced), you scan in the barcode using the reader attached to your bookcase.

Each shelf has a narrow strip of continuously barcoded plastic attached across the width of the bookcase. As each book is replaced, it must be set on the shelf so that it stands, for a moment, between its new neighbours and covers a section of the barcode tape, corresponding to the width of the book.

Whilst in this position, the scanner is used to record the sequence on the tape running up to the front of the book and after the back face. This specifies where the book is and is recorded by the system. The book can then be pushed backwards off the tape and into position. This will automatically update the locations of all the books on that shelf (by an amount which decreases with distance from the replaced book).

The tape also carries human-readable numbers so that the system, when asked, “Where is my copy of Ulysses?” can respond “It’s at indicator 20115 in bookcase 3. It was last accessed one year ago. Your library is now 2301 replacements away from alphabetical ordering”.

#364: Timescale

I’ve really never been good at any of those primary school tasks such as tying my laces (or tie), differentiating between p’s and q’s or telling the time. Unlike people with Dyslexia, who get extensions to complete written exams, asking for extra time to read a clockface seems perpetually self defeating.

The two-hands-at-once thing is just not intuitive. Today’s invention provides the same precision in time telling but without having to interpret all that distracting hand waving (and with a certain additional aesthetic continuity).


The watch face shows a high-resolution sub-region of a disc representing 24hrs. As time passes, the sub-region shown appears to move around this disc (the edge of which might have 24*60 1 minute-divisions marked on it, as well as the hourly numerals).

The exact time is indicated at the pink dot fixed in the middle of the watch.

#363: Flight safe

It’s a little absurd but apparently the world’s airports are now clogged up with a surplus of nail scissors and swiss army knives.

The US Transportation Security Administration (who thinks up these grandiose departmental titles, The Directorate of Official Administrative Nominativism?) said 10 million prohibited items have been seized or voluntarily turned over this year nationwide. So much so that auctioning these items, in small lots online, is actually a pretty profitable sideline for the airport authorities.


So I wondered recently when having to surrender my olive oil-filled can of Baltic herring at an Estonian airport, how do these things get transmitted to their new owners? If any of these confiscated cannisters actually do contain explosive material, then sending them via the post, by loading on a different plane, truck or ship would seem like a pretty bad idea. Imagine the lawsuits if an airport transmits a bomb to some hapless bidder?

Anyway, today’s invention is a simpler approach to those items which are considered too dangerous to enter the cabin but which are not suspected of being explosive. The airport would sell passengers a metal box each, into which they could place their nailfiles, skinning knives and handcuffs. This woud then be locked and the key posted to a passenger’s onward address, enabling their box to be carried aboard but opened only when their journey was complete.

Passengers might be allowed to reuse their box, buying just a new padlock from security for each trip.

#362: Bullettool

In some parts of the world, gunpowder is only about 100 times more expensive, per unit of energy, than gasoline (petrol engines and machine guns have similar levels of energy efficiency, by the way -a surprising 30%). These always seem to be the places where a profusion of weapons constitutes a major barrier to economic development and social stability (think Belfast, eg).

Today’s invention is a simple motor that can be used to do valuable work, in places without cash to buy engines, whilst also soaking up any bullets which happen to be lying around waiting to create further tragedies.


Take an automatic rifle, such as the ubiquitous AK47, and place it handle-down between two metal rails. These are to guide the weapon. A return spring attaches the gun to the wall of the factory. It is pointed through a hole in the wall into an oil drum full of wet sand -oriented so that the long axis of the drum is in line with the barrel (wet sand is particularly effective at slowing bullets -hence sandbags). You might need to weld a couple of drums together lengthwise, but at least you get to reclaim all that lead (as well as the brass cartridges).

The butt end of the weapon can now be attached to eg a mechanical linkage or a hammer. When the gun is set to ‘semiautomatic’ and the trigger pulled, it will repeatedly recoil along the rails, and be returned by the spring. In this way, some of the recoli energy can be used to break rocks, hammer nails or drive production machinery.

The most obvious way to work this is to have a few such weapons linked to a flywheel, so that firing need not be continuous (although using a drum magazine or ammunition belt feed would also make things simpler).