Today’s invention is another tool to help improve the handwashing of hospital medics (a New York Times article recently claimed that washing only happens about 1/3 as frequently as training requires).

All medical staff in contact with patients would wear a brightly coloured bracelet. This would contain an aerosol full of harmless, water soluble paint.

The bracelet would also contain a timer which would ensure that a small spot of bright paint was delivered onto the back of a medic’s hand, say every ten minutes throughout the day.

Appearance of the paint would remind wearers to wash their hands at once. Patients could raise an objection if either the bracelet wasn’t worn or there was a spot of paint on the hand of their examiner.

I’m contemplating getting aloft using a paramotor. If the main ‘glider’ (sail-type parachute) fails, one is ordinarily equipped with a reserve chute, but this is of little use at operational flying levels of ~200m.

Today’s invention is therefore a paramotor fan which can tilt from a horizontal axis to a vertical one, when the pilot realises that a crash landing is imminent. It would automatically jettison the glider canopy once the decision to use the motor in this way was made.

Although the fan could never support a pilot’s weight on its own, it could, in an emergency, greatly reduce the rate of descent, especially if driven at an almost self-destructive speed in this last-ditch mode.

When I see windfarms, several questions occur to me -beyond ‘Do we really think these are a viable energy source?’ Why, for example, is all the gearing and generating equipment located 10m in the air?

Today’s invention is a new form of wind turbine. Two sets of turbine blades rotate about a horizontal axis on top of a column. The outer ends of each set of blades are supported by a bevel-geared ring which bears on a vertical-axis bevel gear wheel near the ground. The blades-and-wheel assembly is free to rotate about this vertical axis in response to changes in wind direction, as usual.

As the wind blows, the gearwheel rotates a generator located conveniently near ground level and protected within the support column (which can be a comparatively low-strength structure). No more swinging the whole affair around in the sky.

Today’s invention attempts to overcome the problem of placing baggage items on an overhead location in public transport.

Often I see people struggling to achieve this, either because the bag is too heavy, or they can’t manage to squat and thrust it into place without endangering people sitting below.

A curved shelf section would be installed at frequent intervals along a carriage/compartment/cabin. A cable would run from a catch attached to the shelf to a pulley in the ceiling.

Attaching bags to a hook on the upper end of the cable would allow them to be hoisted aloft and secured there, without causing a safety issue for those seated below. Use of extra pulleys would increase the mechanical advantage available. The slight slope of the shelf would allow the baggage items to descend later under control.

Today’s invention is a GPS-equipped phone device which is linked to the airbags in one’s car.

In the event that a bag is deployed, a message detailing the location is automatically sent to a preselected list of contacts (including eg the ambulance service, police, next of kin, Twitter, etc).

Today’s invention is a way for ships to avoid being seen at sea.

The ship would carry a large mirror held aloft on stalks.

It would also have a large pontoon supporting metal plates heated directly by the ship’s engines.

This arrangement would generate a synthetic mirage -one in which a distant observer would see a patch of sea, rather than the ship itself.

I’m perpetually irritated by our vacuum cleaner hose blocking up. Today’s invention is a response.

Just as when someone develops a restriction in their airway, this vacuum cleaner would have a sensor fitted to the motor which could detect the rise in current drawn when the hose began to block.

Quickly, it would change the motor direction, causing a sudden reversal of flow or ‘cough’.

This would last for only a fraction of a second, so that there would be no danger that a blockage could emerge from the hose inlet at any speed.

The cough could be repeated several times in succession if the motor load was not rapidly reduced.

There is now great interest in robotic systems which can help retrieve wounded soldiers from a battlefield.

Today’s invention is a hybrid animal/machine system which does not rely on machine intelligence -and might therefore work robustly.

A small terrier is equipped with a light body shield. This is attached to an armoured trolley via a lightweight cable. As the dog runs, the cable becomes slightly taught and the animal’s choice of direction is transmitted to the trolley’s motors via the bend within the cable. The dog can thus direct the trolley, running on powered tracks, but without having to pull it.

When the dog detects a wounded soldier it finds the scented tag attached to a harness with which he or she is equipped. The dog has been trained to drag the tag and drop it into an aperture on the trolley. A winch automatically pulls the soldier aboard and the dog runs back to base pursued closely by the trolley.

Today’s invention is a private key encryption device which relies on fluid dynamics.

Highly viscous flow at low velocity is, near-as-dammit, reversible.

Today’s invention is to use an apparatus such as that in the film linked to above. A message (or an image) would be printed into the body of a gel-like material using eg laser-based rapid prototyping techniques.

This would then be subject to a pattern of low speed rotational shear flow, using a rotary system as shown, to obscure the content. This rotation would however be undertaken by an inner cylinder which could move both circumferentially and axially (as controlled by the user’s choice from a large number of screw cam ‘keys’). The gel could then be transported physically anywhere without the message being decipherable.

It might even be possible to send only images of the gel electronically (ie its local contrast distribution). On receipt of the message, it could be decoded by reversing the action of the original key.

Today’s invention is a browser plugin which remembers what content a user has scrolled through before and, if asked to display it again, does so with the content greyed out. The more showings, the paler the content.

This would alert the user, before starting to re-read any such material, to the fact that this was old news -without having to filter and completely reformat the stories on eg the BBC website, only some of which change in the course of a day.

It would also lessen the frustration associated with coming across content repeated on different sites dressed up in alternative colours, formats and fonts.