NL2014461B1

NL2014461B1 - Personal electronic delivery system and method for delivering a delivery fluid.

Info

Publication number: NL2014461B1
Application number: NL2014461A
Authority: NL
Inventors: Jacob Metz Sybrandus; Hendrik Mulder Gerhard; Hendrik Wolters Hans; Kuipers Johannes
Original assignee: Utvg Global Ip B V
Priority date: 2014-12-31
Filing date: 2015-03-16
Publication date: 2016-10-12

Abstract

The present invention relates toa personal dectronie delivery system and a metbod for delivering a delivery fluid to a person. The system according to the invention comprises: a housing having a first end with an inlet and a second end with an outlet; a fluid path substantially extending between the inlet and the outlet; a buffer for holding a delivery fluid, and connecting means configured to transfer delivery fluid to the fluid path; and a heater that is provided in, at or close tothefluid path configured for heating the delivery fluid such that at least a part of the delivery fluid atomizes and/or vaporizes in the fluid path, and an energy souree configured for providing energy to the heater, wherein the heater comprises a conductor and a porous ceramic layer that is configured to control the atomising and/or vaporization.

Description

PERSONAL ELECTRONIC DELIVERY SYSTEM AND METHOD FOR DELIVERING A

DELIVERY FLUID

The present invention relates to a personal electronic delivery system capable of delivering a delivery fluid to a person. Such system includes so-called E-cigarettes.

Delivery systems, such as E-cigarettes, are known and comprise an inhaling device with an inlet and an outlet that is shaped as a mouth piece. E-cigarettes further comprise a battery and a heater that is provided with energy from the battery. The heater is winded around a so-called wicking material that acts as a buffer, wherein the heater is switched on and off with a flow detector located in the inlet, for example. A buffer comprises the delivery fluid, such as a so-called E-liquid, usually being a mixture of propylene glycol, glycerine, nicotine, and flavourings. The heater vaporises and/or atomises the E-liquid to enable inhaling of the liquid. A problem with conventional E-cigarettes is the insufficient control of heater temperature when the heater is in use. This results in vaporizing and/or atomising of the E-liquid with a relatively large temperature variation such that components in the E-liquid are not only heated, and are burnt in stead. This provides undesirable components in the inhaled fluid that could pose a problem in relation to a person’s health. Furthermore, most conventional E-cigarettes have a buffer embodied as a type of cloth that comprises the E-liquid. Also burning this buffer material may result in undesirable components being inhaled by the person using the E-cigarette. Furthermore, using conventional E-cigarettes may result in release of heavy metals.

The present invention has for its object to provide a personal electronic delivery system, specifically including E-cigarettes, that enable a more controllable atomisation and/or vaporization thereby reducing and/or preventing health problems.

This object is achieved with the personal electronic delivery system according to the present invention, the system comprising: a housing having a first end with an inlet and a second end with an outlet; a fluid path substantially extending between the inlet and the outlet; a buffer for holding a delivery fluid, and connecting means configured to transfer delivery fluid to the fluid path; and a heater that is provided in, at or close to the fluid path configured for heating the delivery fluid such that at least a part of the delivery fluid atomises and/or vaporizes in the fluid path, and an energy source configured for providing energy to the heater, wherein the heater comprises a conductor and a porous ceramic layer that is configured to control the atomising and/or vaporization.

Providing a fluid path from the inlet to the outlet, preferably embodied as a mouth piece, enables inhaling at the outlet to draw/suck in ambient air, for example. This provides a personal electronic delivery system, such as E-cigarettes that also include so-called E-cigars. The heater that is included in the system atomises and/or vaporizes the delivery fluid when the heater is switched on. Switching on the heater can be achieved with the use of a flow controller close to the inlet, for example. Energy is provided to the heater, by an energy source, for example a (rechargeable) battery. The delivery fluid can relate to a mixture of liquids and/or solids, including so-called E-liquids that may comprise a mixture of propylene glycol, glycerine, nicotine and flavourings. It will be understood that other ingredients can also be applied and/or nicotine can be omitted from the mixture.

The heater element comprises a conductor that can be shaped as a plate, wire, foil, tube, foam, rod or any other suitable shape, preferably of a so-called resistance heating material that can be heated by applying an electric current to the conductor of the heater element. The conductor can be of a suitable material, including aluminium, FeAl, NiC, FeCrAl (Kanthal), titanium, and their alloys.

The ceramic layer that is provided on or adjacent the conductor enables effective control of heater temperature thereby preventing burning of components in the delivery fluid and/or other elements of the system, such as buffer material. This improves the quality of the inhaled fluid by preventing undesirable components being present therein.

As a further effect the ceramic layer provides structure and stability to the conductor thereby increasing the strength and stability of the heater as a whole. This is especially relevant in case the system is applied as an E-cigarette. Such E-cigarette is subjected to many movements, vibrations and/or other impacts. For example, the increased stability prevents malfunctioning and/or prevents contact of the heater with other components of the system, including buffer material such as a cloth that is drenched in E-liquid. This prevents undesired burning of components. Furthermore, the ceramic layer prevents the release of heavy metals.

Also the ceramic layer enables adsorption and/or absorption of the E-liquid in the pores of the ceramic layer.

In a presently preferred embodiment according to the invention the ceramic layer has a thickness in the range of 5-300 pm, preferably 10-200 pm, more preferably 15-150 pm and most preferably a thickness is about 100 pm.

By providing the ceramic layer with a sufficient thickness the stability and strength of the heater is improved. Furthermore, the insulation is increased, enabling control of heat transfer and/or heat production. The thickness of the ceramic layer can be adapted to the type of E-liquid and/or the specific system and/or the desired characteristics. This flexibility provides a further advantage of the system according to the invention.

Preferably, the ceramic layer is provided on or at the conductor with plasma oxidation. The heater element is preferably made from a titanium material, or other suitable material, on which a porous metal oxide layer, such as titanium oxide, is grown with plasma electrolytic oxidation. Plasma electrolytic oxidation enables that a relative thick titanium layer is grown from the titanium (>130 pm) by oxidizing (part of) the titanium to titanium oxide. The resulting layer is a porous, flexible and elastic titanium oxide ceramic. Plasma electrolytic oxidation (>350 - 550 V) requires much higher voltage compared to standard anodizing (15-21 V). At this high voltage, micro discharge arcs appear on the surface of the titanium, or other material, and cause the growth of the thick (titanium) oxide layer. Other metals, such as aluminium or nichrome, may also be used for the heater element of the system according to the present invention. For example, results have shown that a ceramic layer can be achieved on an aluminium foil of about 13 pm thickness, with a flexible and elastic ceramic layer. One of the advantageous effects of using plasma oxidation to provide the ceramic layer is that due of the growth of the layer from the metal during oxidation the adherence of the ceramic layer to the metal is excellent.

In a presently preferred embodiment the structure of the heating element comprises a thin wire of titanium, aluminium, or any other valve metal. Such valve metal is capable of forming an oxide layer which forms a protective layer on its surface and then stops it to oxidize further. In a presently preferred embodiment titanium is used for the heating element considering its relatively high resistance achieving a relatively fast heating process. The wire is coated on the other side through plasma oxidation. Plasma oxidation is done by placing the titanium wire in an electrolyte. For example, the electrolyte comprises 15 g/1 (NaPOsT and 8 g/1 Na2Si03.5H20. The electrolyte is maintained at a temperature of 25°C through cooling. The wire is used as an anode and placed in a container containing the electrolyte. Around the wire a stainless steel cathode is positioned. A current density is maintained between the wire and cathode of about 0.15 A/cm2. The current is applied in a pulsed mode of about 1000 Hz. The potential increases rapidly to about 500 Volt between the wire and the cathode. This creates a plasma oxidation process on the anode wire and creates a ceramic layer. As the wire is small sized (100 micron) it has a relative high electrical resistance 61 Ohm/m. By applying a current to the wire, the wire heats up. It will be understood that process parameters may depend on the structure of the heating element and/or the dimensions thereof.

In an alternative embodiment a plate of metal, for example aluminium, titanium or other valve metal, is coated on at least one side with a ceramic layer using plasma oxidation, for example. Due to metal plate resistance its temperature increases when a current is applied. Also, a structure can be etched into the metal providing metal strips of metal having a relatively high resistance. The etching can be performed using electrochemical machining, for example.

Alternative manufacturing methods for the heater element include sintering or spark plasma sintering, oxidation of the surface layer of the metal by heating in oxygen rich environment, anodizing, and plasma spraying. Also, it would be possible to deposit an aluminium, or other material, coating on the conductor of the heater element, for example with arc spraying, and to oxidize the deposited material to an oxide with plasma electrolytic oxidation.

In a presently preferred embodiment according to the present invention, the heater comprises a spiralled metal wire as the conductor with the wire being provided with the ceramic layer.

Providing the heater with a spiralled metal wire an effective atomisation and/or vaporisation of delivery fluid can be achieved. The spiralled metal wire is preferably provided in the fluid path. This achieves an effective heating of the E-fluid.

Alternative configurations for the heater in a wire configuration include a straight wire, single or multiple layer solenoid wire, toroid single or multiple layer, and flat coil. Alternative configurations for the heater in a foil or plate configuration include a flat, round, rectangular shape, spiral wound, and folded configuration. Further alternative configuration for the heater in a tube configuration include a metallic tube with coated porous ceramic layer and optionally provided with a (static) mixing structure or helix structure, tube shape of foil/plate, and spiral wound foil/plate. An even further alternative configuration of the heater in a foam configuration includes a sponge structure.

In an embodiment according to the present invention the central axis, or longitudinal direction of the spiralled metal wire, is positioned substantially transversally to the main fluid flow direction in the fluid path.

In a presently preferred embodiment according to the invention the spiralled heater has a central axis that is provided substantially in a longitudinal direction of the fluid path. Even more preferably, the fluid path is designed such that the inhaled fluid passes through the spiralled wire in the longitudinal direction. This enhances the atomisation and/or vaporisation, thereby improving control of these processes and/or reducing the amount of the required energy to perform these processes. This improves the lifetime of the system according to the invention.

In a presently preferred embodiment the ceramic layer is provided with porosity such that the delivery fluid is transferred from the buffer to the vicinity of the conductor.

By providing a porous ceramic layer it is possible to configure the ceramic layer such that the delivery fluid is transferred through or along the ceramic layer enabling delivery fluid to transfer from a buffer to the conductor. This prevents the need to provide a separate buffer such as a buffer cloth.

Preferably, the ceramic layer has a porosity in the range of 10-80%, preferably 15-50%, more preferably 20-30% and most preferably the porosity is about 25%. It was shown that especially the porosity in a range of 20-30% provides a optimum in the performance of specifically the ceramic layer and the heater as a whole. Furthermore, it is shown that using plasma oxidation to provide the ceramic layer is beneficial in that it enables control of the porosity of the produced layer.

In a presently preferred embodiment according to the present invention the buffer substantially surrounds the heater, wherein the buffer is provided with openings configured for transferring delivery fluid to the heater.

Providing the buffer substantially around the heater enables fluid to be delivered through a small opening(s) in the inner surface (area) of the buffer compartment which is filled with liquid through capillary action of the e-liquid/delivery fluid. The heating element with porous ceramic layer is positioned on the other side of this hole. Liquid is transferred to the heating element by capillary action. If the heating element is heated by an electric current, liquid is evaporated from the ceramic layer and the liquid in the opening(s) is heated by the element. Due to the higher temperature caused by the heating elements the viscosity decreases and the liquid is adsorbed on the ceramic layer through the holes. The holes are preferably made in a metal tube since this does not burn. This provides a robust supply of delivery fluid to the heater.

In a presently preferred embodiment according to the invention the system further comprises a power and/or current increasing circuit configured for providing a power increase when the heater is switched on.

By providing the power and/or current increasing circuit the power can temporarily be increased when switching on the heater. Such circuit may comprise a number of capacitors and/of coils, with the number being one or more. The circuit enhances the effect of the heater and/or reduces the requirements for the power supply.

In a presently preferred embodiment a capacitor, preferably a so-called super-capacitor, is included in a circuit that provides a peak current, preferably when a user of an E-cigarette starts to inhale. When activating the heater to atomize and/or vaporize the fluid, the heater temperature has to be increased. By providing a (super) capacitor this temperature increase can be performed faster and almost instantaneously. This enables the device, for example an E-cigarette, to almost directly provide a fluid at its outlet comprising atomized and/or vaporized delivery fluid. The current increase/peak when activating the heater element leads to heat development in het heater element that is used to atomize and/or vaporize the delivery fluid. The heater element according to the invention comprises a porous ceramic layer that is preferably capable of absorbing and/or adsorbing delivery fluid. This enables the heater element to start directly with the atomizing and/or vaporizing. As a further advantageous effect the battery is not required to provide the peak current when activating the heater element. This enables providing a smaller battery, thereby enabling dimensioning an E-cigarette in conformity with the size of a conventional cigarette, for example. Furthermore, with the additional circuit comprising a (super) capacitor the battery is not subjected to peak demands and can, therefore, be operated at a more constant level. This improves the lifetime of the battery. The capacitor can be charged by the battery after the heater element is deactivated. In an advantageous embodiment the heater element is made from a titanium material that has a relatively low resistance at low temperature (e.g. 20°C) and a high resistance at a higher temperature. This enables providing a higher current to the heater element when activating the heater element, while after the heater element reached its optimal operating temperature the applied current is lower. In fact, the resistance of titanium at the vaporisation and/or atomisation temperature is optimal for the battery. With the use of the (super) capacitor the battery is no longer limiting the (minimum) resistance of the heater element, thereby enabling an improved design of the heater element and the device comprising this heater element. Especially the combination of a super capacitor with titanium wire conductor appears beneficial.

In one of the presently preferred embodiments according to the invention the super capacitor is connected to a charge-connector configured for connecting the super capacitor to an external power source for charging the super capacitor. This enables external charging of the super capacitor without the need for the battery to supply the power for charging the super capacitor. In a further preferred embodiment system does not include a battery. In this embodiment the super capacitor supplies all required energy and is charged from an external power supply. Preferably, the super capacitor has a capacity of 12 Farad, or more. This reduces the number of components of the system, reduces system weight, and immediately provides energy for vaporization/atomization. Optionally, the system is charged in the cigarette box, for example using a rechargeable battery.

In a presently preferred embodiment the conductor of the heater element is made of NiCr and preferably of Titanium. The resistance of Titanium increases more rapidly with temperature as compared to NiCr.

The present invention also relates to a method for delivering the delivery fluid to a person, comprising the steps of: providing a personal electronic delivery system as herein described, inhaling at the second end of the housing to provide a subnormal pressure in the fluid path such that the ambient air is sucked into the inlet; and atomising and/or vaporising at least a part of the delivery fluid with the heater and delivering at the outlet.

The method provides the same effects and advantages as described for the system. The method provides effective means to deliver a delivery fluid to a person, for example to provide the feel of tobacco smoking, without increasing health problems by burning components of the delivery fluid and/or system.

Preferably, the heater comprises a conductor with a ceramic layer. More preferably, the ceramic layer is provided using plasma oxidation. Plasma oxidation is preferably used as it enables control of the porosity and/or thickness of the ceramic layer.

Preferably, in use, the heater reaches a temperature in the range of 150-750°C, preferably 200-500 °C, and more preferably 250-400°C. As shown, at these temperatures a good atomisation and/or vaporisation of the delivery fluid can be achieved.

Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof wherein reference is made to the accompanying drawings, in which:

Figure 1 shows an E-cigarette according to the invention;

Figure 2 A-V shows configurations of the heater element according to the invention; Figure 3 A-B shows a setup of a plasma oxidation chamber to produce the heater element of figure 2; and

Figure 4 shows the Voltage as function of time in the manufacturing of the heater element in the chamber of figure 3;

Figure 5 shows a heater element according to the invention;

Figure 6 A-B shows embodiments of a power/current increasing circuit;

Figure 7 shows the resistance of electric heater elements in relation to temperature for titanium and NiCr; and

Figure 8 an alternative embodiment of an E-cigarette according to the invention. E-cigarette 2 (Figure 1) comprises battery assembly 4 and atomizer assembly 6. In the illustrated embodiment atomizer assembly 6 is disposable. It will be understood that the invention can also be applied to systems with other configuration and that the illustrated embodiments is for exemplary purposes only. Details, including connections between components, that are known to the skilled person from conventional E-cigarettes have been omitted from the illustration to reduce the complexity of the drawing.

Battery assembly 4 comprises housing 8, (LED) indicator 10 with air inlet 12, air flow sensor 14, circuit 16 and battery 18. Air from inlet 12 is provided with air path 20 to sensor 14. Circuit 16 comprises an electronic circuit board that is connected to the relevant components of system 2. Battery 18 can be a rechargeable battery including the required connections to enable recharging. Battery assembly 4 has air inlets 22 and connector 24 to connect battery assembly to atomizer assembly 6.

Atomizer assembly 6 comprises housing 26 with air path 28 that is surrounded with buffer 30 comprising the E-liquid (for example a mixture of glycerol, propylene glycol, nicotine). Buffer material may include wicking material such as silica, cotton, etc.) or buffer 30 can be provided by other buffer means. In the illustrated embodiment heater element 32 is provided at or around the perimeter of air path 28. In one of the preferred embodiments heater element 32 comprises a wire of metallic titanium core 34 with ceramic titanium oxide layer 36 around metallic core 34. The E-liquid is absorbed and/or adsorbed in the porous ceramic layer. Wire 32 is heated by passing an electric current through metallic titanium core 34. Wire 32 is heated and the E-liquid is evaporated and/or atomized. The mixture is provided to outlet 38 of air path 28 at mouth piece 40.

Heater 32 achieves an improved temperature control and the ability to control the amount of E-liquid evaporating in time by varying the characteristics of the porous ceramic layer 36, such as thickness, size of pores, and porosity.

When inhaling at outlet 38 an under pressure in air paths 20, 28 is achieved. Air is sucked in through inlets 12, 22. Sensor 14 detects an air flow and circuit board 16 sends an indication signal to indicator 10. Battery 18 provides electricity to heater 32 that heats the E-liquid supplied from buffer 30 and vaporizes and/or atomizes the liquid such that a user may inhale the desired components therein.

In the illustrated embodiment heater 28 has its longitudinal axis substantially parallel to air path 28. It will be understood that other configurations are also possible according to the invention.

Optionally, heater 28 is surrounded by buffer 30. The surface area of buffer 30 is preferably provided with (small) openings that are filled with E-liquid from the buffer. Capillary action transfers liquid from the openings to heater element 30. The openings are preferably made in a metal tube-like surface of buffer 30 to prevent burning.

Several embodiments of a heater element according to the invention will be illustrated. Heater 42 (Figure 2A) comprises a resistance heating material 44a as conductor and porous ceramic layer 44b. Heater 46 (Figure 2B) is wound as a solenoid 48 (Figure 2C) similar to heater 28 as illustrated in Figure 1. In an alternative configuration heater 50 is configured as a toroid (Figure 2D), or flat coil 51 (Figure 2E), or flat spiral 52 (Figure 2F), for example.

In the illustrated embodiment of system 2 buffer 30 is provided around air path 28 and heater 32 (see also Figure 2G). In an alternative embodiment liquid reservoir 54 is provided inside the solenoid of heater 56 (Figure 2H).

Further alternative configurations include heater 58 (Figure 21) wound as toroid structure with liquid inside toroid structure and air flow around toroid structure, and heater 60 (Figure 2J) as a flat coil. Also, heater 62 (Figure 2K) may comprise a layer of path of resistance heating material 64 as conductor on coated porous ceramic layer 66, or alternatively heater 68 may comprise a conductor layer 70 with coated porous ceramic elements or spots 72 provided thereon (Figure 2F). Alternatively, heater 74 comprises conductor layer 76 and ceramic layer 78 (Figure 2M), and optionally additional ceramic spots 80 (Figure 2N). Another embodiment comprises porous ceramic layer 82 with conductor 84 wound in a spiral configuration (Figure 20).

Other embodiments include conductor tube 86 with static mixing form 86a coated with ceramic layer 88 (Figure 2P and 2Q). As a further alternative, conductor 90 is a tube (Figure 2R) with a ceramic layer 92. Tube 90a can be filled with liquid on the inside and having air flow on the outside (Figure 2S) or tube 90b has air flow on the inside and liquid buffer on the outside (Figure 2T). Optionally, a ceramic layer is provided on the inside and the outside of tube 90. Also, tube 90 may comprise a number of smaller tubes or wires 94 with resistance heating material and ceramic material (Figure 2U). A further alternative configuration (Figure 2V) involves resistance heating metallic foam or sponge 96 coated with porous ceramic material 98.

The disclosed embodiments for heater 32 provide examples of heaters according to the invention that can be applied to systems 2.

Heater elements according to the invention are preferably manufactured using plasma electrolytic oxidation. As an example, for illustrative reasons only, below some manufacturing methods for some of the possible configurations for the heater element according to the invention will be disclosed.

In a first embodiment of the heater element, plasma electrolytic oxidation of titanium wire that is directly connected to an anode is performed.

For the plasma electrolytic oxidation use is made of a plasma electrolytic chamber 102 (Figure 3 A). Work piece 104 is connected to the anode 106. Work piece 104 is clamped/fixed between two screws or clamps 108 that are connected to the ground/earth (anode 104) of a power supply. In the illustrated embodiment cathode 110 comprises stainless steel honeycomb electrode 112 that, in use, is placed at close distance above work piece 104. Electrolyte 114 flows between electrode 112 and anode 106, and effectively flows upwards through honeycomb electrode 112 together with the produced oxygen and hydrogen. Electrolyte effluent 116, together with the hydrogen and oxygen, is then cooled and optionally returned to chamber 102. In the illustrated embodiment the temperature of electrolyte 114 increases from around 11°C entering plasma oxidation chamber 102 to 25 °C exiting chamber 102 and is then cooled off using a heat exchanger (not shown).

In the illustrated chamber 102 two power supplies (Munk PSP family) are connected in series: one of 350 Volt and 40 Ampere and a second of 400 Volt and 7 Ampere resulting in a maximum of 750 Volt and 7 Ampere with resulting maximum power of 5.25 kW. The power supplies can be connected directly to anode 106 and cathode 110 resulting in direct current (DC) operation of the plasma. An optionally added switching circuit provides the option to operate the plasma with DC pulses. The frequency of the pulses can be set between DC and 1 kHz and different waveforms can be chosen (block, sine, or triangle). Plasma oxidation is preferably performed in a pulsed current mode with a frequency (on-off) of about 1000 Hz, preferably with the current set at a fixed value and the voltage increases in time as a result of growing of the porous oxide layer. Current between 1 and 7 Ampere can be used to produce a ceramic layer.

To produce a heater element according to the invention, in chamber 102 titanium wire 202 (Figure 3 B) is placed as work piece 104 on top of a titanium plate 204 that is connected to the stainless steel anode. Optionally, the anode is directly connected to wire 202. The electrolyte comprised 8 g/1 NaSi03*5H20 and 15 g/1 (NaPCBV Titanium wire is used made from titanium grade 1, with a diameter of 0.5 mm and 60 cm in length. The wire is coiled and connected to the anode. A potential higher than 500 volts is applied between the anode and cathode resulting in micro arc discharges on the surface of the titanium wire. On the surface of the wire, the metallic titanium is oxidized to titanium oxide with addition of silicates and phosphates from the electrolyte. The metallic layer is converted to a porous ceramic layer containing titanium oxides, phosphates and silicates. This results in a heater element 302 (Figure 5) according to the invention.

Current increasing circuit 402 (Figure 6A) comprises battery 404, trafo 406, heater element 408 and (super) capacitor 410. Other components in circuit 402 include diode 412, resistance 414, switch 416 responding to inhaling, transistor 418. It will be understood that components in circuit 402 can be replaced with other components and/or additional components can be applied. For example, alternative circuit 420 (Figure 6B) comprises battery 422, heater element 424, capacitor 426, switch 428, resistor 430 and diode 432.

When starting to inhale capacitor 410, 426 supplies additional current to heater element 408, 424 to accelerate the temperature increase of heater element 408, 424 and to start atomizing and/or vaporizing almost immediately. Preferably, the heater element is of a titanium material that exhibits a relatively low resistance at room temperature and a higher resistance at an increased temperature thereby enabling a fast response time to the activation signal.

In a presently preferred embodiment the conductor of the heater element is made of NiCr and preferably of Titanium. The resistance of Titanium (Figure 7) increases more rapidly with temperature as compared to NiCr. This is illustrated with the linear relation for NiCr (y=0.001 1 x+2.164) as compared to the linear relation for Titanium (y=0.0104x+1.5567) defining the linear relation of the measured resistances at specific temperatures.

In a further embodiment of E-cigarette 502 (Figure 8) heater 32 is supplied with energy through connector 504 from super capacitor 506. Capacitor 506 is charged via external connector 508. Capacitor 506 can be charged (semi)-directly and/or indirectly. Such indirect charging can be performed in connection with cigarette box 510 having cigarette storage compartment 512 and battery compartment 514 with battery 516. In a charging state charge connector 518 contacts connector 508 and super capacitor 506 is being charged. In the illustrated embodiment battery 516 is rechargeable through connector 520.

Three experiments were done: 1) 0.5 Ampere for 15 minutes, 2) 1 Ampere for 15 minutes and 3) 2 Ampere for 15 minutes. The mass and diameter of the wire was measured before and after plasma electrolytic oxidation. The wire was placed in water for 5 minutes and the mass was measured as an indication of the amount of water adsorbed on the wire. The voltage as a function of time of the three different current settings can be seen in Figure 4, and some further material information before and after oxidation is presented in Table 1.

Table 1: Material information

Ceramic wires were manufactured at different process conditions, including with 5 Ampere (wire 1) and 1 Ampere (wire 2) for processing time of an hour. The results are shown in Table 2.Table 2: Thickness of ceramic layer porosity and adsorption of two ceramic titanium wires

Wire 1: Before plasma electrolytic oxidation (PEO) L - 0.5 m, D = 0.500 mm, R = 1.2 Ω, Rcaicuiated = 2.44 Ω/m, Adsorption (water) = 4 μΐ Wire 1: After PEO (5 A for 60 minutes) L = 0.5 m, D = 0.610 mm, R - 1.3-1.4 Ω, Adsorption (water) = 21 μΐ, Porosity = 44 %

Wire 2: Before PEO: L = 0.5 m, D = 0.500 mm, V = 9.8 e-8 m3, m = 4.2992 e-4 kg, p = 4379 kg/m3 Wire 2: After PEO (1 A for 60 minutes) L = 0.5 m, D = 0.5610 mm, V = 1.236 e-8 m3, m = 4.512 e-4 kg, p = 3650 kg/m3,nvide layer = 2.13 e-5 kg, Voxide layer — 2.56 e-8 m , M^estimate with0utporosity — 4.452 e-5 kg, Porosity — 50 %, Calculated adsorption = 12.8 μΐ

It will be understood that for alternative wires other conditions would apply. For example, for a wire having a diameter of 0.1 mm Rcaicuiated = 61 Ω/m. Such wire with a length of 6.5 cm will give a resistance of 4 Ω. With an oxide thickness of 100 μπι an amount of 1.3 μΐ is adsorbed. 150 μπι gives 3.1 μΐ and 200 μπι gives 5.4 μΐ.

The experiments illustrate the manufacturing possibilities of the heater element for the system according to the present invention.

Further experiments have been conducted to produce other configurations for the heater. In one such further experiment a metal foil, preferably an aluminium foil, was used as starting material on which a porous metal (aluminium) oxide layer is provided, preferably in a plasma electrolytic chamber that is described earlier. Table 3 shows measured values of plasma electrolytic oxidation with constant current at 5 ampere for 9 minutes. Aluminium foil of 13 pm thickness was oxidized with a resulting thickness of aluminium oxide of 13 pm.Table 3: Voltage, current, temperature of electrolyte going in the plasma oxidation chamber (Tin) and going out the plasma oxidation chamber (Teff) for constant current of 5 A.

Table 4 shows the reproducibility of the process.

Table 4: Voltage, current, temperature of electrolyte going in the plasma oxidation chamber (Tin) and going out the plasma oxidation chamber (Teff) for constant current of 5 A.

Table 5 shows the voltage and current for plasma electrolytic oxidation of aluminium foil at constant current of 2 A. Result was a 13 pm thick aluminium oxide layer.

Table 5: Voltage and current of plasma electrolytic oxidation with constant current of 2A.

Table 6 shows the voltage and current of the plasma electrolytic oxidation of aluminium foil with pulsed constant current of 1 kHz at 5 Ampere.

Table 6: Voltage and current of pulsed constant current of 1 kHz

In a further experiment, plasma electrolytic oxidation was used to provide a porous, flexible and elastic ceramic layer of >70 pm on titanium foil. Plasma electrolytic oxidation grows a titanium oxide layer which is known to be ceramic (Ti02). Electrolyte was used with 8 g/1 Na2Si03*5H20 (Natrium metasilicate pentahydrate) and 15 g/1 (NaP03)r, (Natrium hexametaphosphate). The electrolyte is pumped into the reaction chamber to act as the electrolyte and as a coolant. Titanium foil was used from titanium grade 2 with a thickness of 124 pm. In the manufacturing process the voltage increases as a function of time. This increase signifies an increased resistance and can possibly be explained by the growth of the titanium oxide (TiOx) layer. A thicker TiOx layer acts like an insulating layer between the metal and electrolyte. The resulting Voltage development in time can be seen in Table 7.

Table 7: Voltage and current as function of time for production of ceramic layer on titanium foil with plasma electrolytic oxidation

The resulting foil structure can be processed further involving electrochemical machining. For example, use can be made of dissolution of Titanium grade 2 to make perfect squared shaped channels. With electrochemical machining (ECM) Titanium grade 2 is locally dissolved in a very controlled manner until the ceramic layer is reached. The finished result has to be well defined channels with squared edges and no residue on top of the ceramic layer. The ECM process is used with a cathode with the inverse shape of the product placed on top of a Titanium plate that serves as the anode. A potential is placed between the cathode and anode causing the anode to dissolve. Electrolyte concentration is 5 M NaN03. Current density can be varied from 20-150 A/cm2. The best results were realized with current densities of >60 A/cm2. Current is operated in a pulsed mode with the time the current is on and off can be varied. Best results were realized with on/off ratio of 16 - 80 and pulse on from 0.05 until 10 ms and pulse off from 1 ms until 160 ms. This additional processing step may also be applied to other configurations for the heater.

In a presently preferred embodiment the heater element is made from a titanium wire, or less preferably from NiCr wire. Figure 8 shows the resistance of electric heater elements in relation to temperature for both materials. As mentioned earlier the use of titanium for the heater element is beneficial.

The above described experiments illustrate the possibility to manufacture the different configurations of the heater element and to implement such configuration in an E-cigarette, for example.

The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, wherein the scope of which many modifications can be envisaged.

CLAUSES 1. Personal electronic delivery system, comprising: a housing having a first end with an inlet and a second end with an outlet; a fluid path substantially extending between the inlet and the outlet; a buffer for holding a delivery fluid, and connecting means configured to transfer delivery fluid to the fluid path; and a heater that is provided in, at or close to the fluid path configured for heating the delivery fluid such that at least a part of the delivery fluid atomises and/or vaporises in the fluid path, and an energy source configured for providing energy to the heater, wherein the heater comprises a conductor and a porous ceramic layer that is configured to control the atomizing and/or vaporization. 2. System according to clause 1, wherein the ceramic layer is provided on or at the conductor with plasma oxidation. 3. System according to clause 1 or 2, wherein the ceramic layer has a thickness in the range of 5-300 pm, preferably 10-200 pm, more preferably 50-150 pm, and most preferably the thickness is about 100 pm. 4. System according to one or more of the foregoing clauses, wherein the heater comprises a valve metal, preferably titanium. 5. System according to one or more of the foregoing clauses, wherein the heater comprises a spiralled metal wire as the conductor, wherein the wire is provided with the ceramic layer. 6. System according to clause 5, wherein the spiralled heater has a central axis that is provided substantially in the longitudinal direction of the fluid path. 7. System according to one or more of the foregoing clauses, wherein the ceramic layer is provided with a porosity such that the delivery fluid is transferred from the buffer to the vicinity of the conductor by the ceramic layer. 8. System according to one or more of the foregoing clauses, wherein the ceramic layer has a porosity in the range of 10-80%, preferably 15-50%, more preferably 20-30%, and most preferably the porosity is about 25%. 9. System according to one or more of the foregoing clauses, wherein the buffer substantially surrounds the heater, wherein the buffer is provided with openings configured for transferring delivery fluid to the heater. 10. System according to one or more of the foregoing clauses, further comprising a power and/or current increasing circuit configured for providing a power and/or current increase when the heater is switched on. 11. System according to clause 10, wherein the circuit comprises a super-capacitor. 12. System according to clause 11, wherein the super-capacitor is connected to a charge-connector configured for connecting the super-capacitor to an external power source for charging. 13. Method for delivering a delivery fluid to a person, comprising the steps of: providing a system according to one or more of the foregoing clauses; inhaling at the second end of the housing to provide a subnormal pressure in the fluid path such that ambient air is sucked into the inlet; and atomizing and/or vaporizing at least a part of the delivery fluid with the heater and delivering at the outlet. 14. Method according to clause 13, further comprising the step of providing the heater with a conductor having a ceramic layer. 15. Method according to clause 14, wherein providing the ceramic layer comprises plasma oxidation. 16. Method according to clause 13, 14 or 15, wherein, in use, the heater reaches a temperature in the range of 150-750°C, preferably 200-500°C, more preferably 250-400°C. 17. Method according to one or more of the clauses 13-16, further comprising the step of providing a power and/or current increasing circuit comprising a super-capacitor.

Claims

A personal electronic delivery system, comprising: a housing provided with a first end with an inlet and a second end with an outlet; a fluid path that extends substantially between the inlet and the outlet; a buffer for holding a delivery fluid and connection means configured for transferring delivery fluid to the fluid path; and a heating element provided in, on or near the fluid path configured to heat the delivery fluid such that at least a portion of the delivery fluid is atomized and / or evaporated in the fluid path, and an energy source configured to provide energy to the heating element, wherein the heating element comprises a conductor and a porous ceramic layer configured to control atomization and / or evaporation.

The system of claim 1, wherein the ceramic layer is provided on or near the plasma oxidation conductor.

A system according to claim 1 or 2, wherein the ceramic layer has a thickness in the range of 5-300 µm, preferably 10-200 µm, more preferably 50-150 µm and most preferably has a thickness of about 100 p.m.

System according to one or more of the preceding claims, wherein the heating element comprises a metal, preferably titanium.

System as claimed in one or more of the foregoing claims, wherein the heating element comprises a spiral-shaped metal wire as a conductor, wherein the wire is provided with the ceramic layer.

The system of claim 5, wherein the spiral-shaped heating element has a central axis that is substantially provided in the longitudinal direction of the fluid path.

A system according to any one of the preceding claims, wherein the ceramic layer is provided with a porosity such that the delivery fluid is transferred from the buffer to the vicinity of the conductor through the ceramic layer.

A system according to any one of the preceding claims, wherein the ceramic layer has a porosity in the range of 10-80%, preferably 15-50%, more preferably of 20-30% and most preferably the porosity approximately 25%.

A system according to any one of the preceding claims, wherein the buffer substantially surrounds the heating element, wherein the buffer is provided with openings configured for transferring delivery fluid to the heating element.

System according to one or more of the preceding claims, further comprising a power and / or current increasing circuit configured to provide a power increase as soon as the heating element is switched on.

The system of claim 10, wherein the circuit comprises a super-capacitor.

The system of claim 11, wherein the super-capacitor is connected to a charging connection configured to connect to an external energy source for charging.

A method for delivering a delivery fluid to a person, comprising the steps of: providing a personal electronic delivery system according to one or more of the preceding claims; inhaling at the second end of the housing to provide a vacuum in the fluid such that ambient air is sucked into the inlet; and atomizing and / or vaporizing at least a portion of the delivery fluid with the heating element and delivering to the outlet.

The method of claim 13, further comprising the step of providing the heating element with a conductor with a ceramic layer.

The method of claim 14, wherein providing a ceramic layer comprises plasma oxidation.

A method according to claim 13,14 or 15, wherein, in use, the heating element has a temperature in the range of 150-750 ° C, preferably 200-500 ° C, and more preferably 250-400 ° C.

The method of any one of claims 13-16, further comprising providing a power and / or current increasing circuit comprising a super-capacitor.