# US 2014/0151582 A1 · Droplet Dispensing Device and Light Source Comprising Such a Droplet Dispensing Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151582 A1 - Document ID: US20140151582A1 - Status: Published application - Kind: A1 - Application number: 14/110,048 - Filed: 2012-04-02 - Published: 2014-06-05 - Earliest claimed: 2011-04-05 - Assignees: ETH Zurich - Inventors: Bob Rollinger; Reza Abhari; Andrea Giovannini; Ian Henderson - Web page: https://patentgrep.com/patent/US20140151582A1 ## CPC - H05G 2/0023: {Constructional details of the ejection system} - B05B 1/02: designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, {or having an outlet of particular shape}(B05B1/26, B05B1/28, B05B1/34 take precedence) - B05B 17/0623: {coupled with a vibrating horn} - H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321) - B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D) ## Abstract A droplet dispensing device includes a reservoir for receiving a liquid material, an outlet nozzle in fluid communication with the reservoir and a piezoelectric actuating means acting on the liquid material at the outlet nozzle to exit the outlet nozzle in a sequence of droplets. A piezoelectric actuating means that includes a piston, which is actuated by a piezoelectric actuator at one end and dips the other, free end into the liquid material is provided just upstream of the outlet nozzle. ## Claims ### Claim 1 A droplet dispensing device, comprising: a reservoir for receiving a liquid material; an outlet nozzle in fluid communication with said reservoir; and a piezoelectric actuating means (29, 30, 32) acting on said liquid material at said outlet nozzle such that said liquid material exits said outlet nozzle in a sequence of droplets, wherein said piezoelectric actuating means comprises a piston, which is actuated by a piezoelectric actuator at one end and dips the other, free end into said liquid material just upstream of said outlet nozzle. ### Claim 2 (depends on 1) The droplet dispensing device as claimed in claim 1, wherein said liquid material is a molten material and said reservoir is heated by a heating means to keep said molten material in the molten state. ### Claim 3 (depends on 2) The droplet dispensing device as claimed in claim 2, wherein said reservoir is surrounded by an outer cylinder and said heating means comprises a resistive heater, which is wound around said outer cylinder and said outlet nozzle and thermally and mechanically fixed to said outer cylinder. ### Claim 4 (depends on 2) The droplet dispensing device as claimed in claim 2, wherein said reservoir and said outlet nozzle are enclosed by a band-heater. ### Claim 5 (depends on 1) The droplet dispensing device according to claim 1, wherein a filter is provided upstream of the outlet nozzle. ### Claim 6 (depends on 1) The droplet dispensing device according to claim 1, wherein said outlet nozzle, said piston, and said filter, respectively, are detachably coupled to said reservoir. ### Claim 7 (depends on 1) The droplet dispensing device according to claim 1, wherein said outlet nozzle is configured to deliver a continuous stream of droplets of said liquid material at a desired frequency when said piston is periodically excited by means of said piezoelectric actuator. ### Claim 8 (depends on 1) The droplet dispensing device according to claim 1, wherein said outlet nozzle comprises a separate nozzle disk, which is retained in a nozzle casing and is detachably coupled to said reservoir by a clamping device. ### Claim 9 (depends on 1) The droplet dispensing device according to claim 1, wherein said outlet nozzle comprises a one-piece nozzle unit, which is detachably coupled to said reservoir by a clamping device. ### Claim 10 (depends on 8) The droplet dispensing device according to claim 8, wherein said nozzle disk is made of a metal or ceramic and comprises a micro-machined nozzle orifice. ### Claim 11 (depends on 1) The droplet dispensing device according to claim 1, wherein means for applying a pressure to the liquid material in the reservoir is provided, so that said liquid material is urged from the reservoir into said outlet nozzle. ### Claim 12 (depends on 11) The droplet dispensing device according to claim 11, wherein said pressure applying means comprises a connector tube leading to the interior of said reservoir. ### Claim 13 (depends on 1) The droplet dispensing device according to claim 1, wherein said reservoir comprises a cover at a side opposite to said outlet nozzle, said actuated piston is mounted on said cover, and said piezoelectric actuator is arranged between said cover and said piston to generate displacements of said actuated piston in order to induce pressure waves in the liquid material at the outlet nozzle to impose a desired frequency to said sequence of droplets. ### Claim 14 (depends on 1) The droplet dispensing device according to that claim 1, wherein said reservoir is suspended at a side opposite to said outlet nozzle in a casing by means of a thermally insulating flange and said piezoelectric actuator is arranged between the flange and the casing. ### Claim 15 (depends on 1) The droplet dispensing device according to claim 1, wherein said reservoir is provided with a cooling system for cooling the piezoelectric actuator to maintain a temperature of the piezoelectric actuator below detrimental temperatures. ### Claim 16 (depends on 15) The droplet dispensing device according to claim 15, wherein said cooling system is arranged outside said reservoir with a defined heat path to said piezoelectric actuator. ### Claim 17 (depends on 13) The droplet dispensing device according to claim 13, wherein a mechanical preload mechanism is provided for said piezoelectric actuator. ### Claim 18 (depends on 13) The droplet dispensing device according to claim 13, wherein a heat shield is provided for at least part of said piston, which reduces a heat flux from the liquid material to said piezoelectric actuator. ### Claim 19 (depends on 1) The droplet dispensing device according to claim 1, wherein said reservoir and said outlet nozzle are part of a replaceable cartridge, which is arranged in a casing and which is thermally insulated from said casing by insulating means. ### Claim 20 (depends on 1) A light source for producing extreme ultraviolet or soft x-ray light, comprising: a chamber that contains a production site for producing extreme ultraviolet or soft x-ray light; the droplet dispensing device of claim 1 for dispensing droplets of a liquid material into said production site, the liquid material being capable of radiating extreme ultraviolet or soft x-ray light when excited into a higher energy state; and irradiating means for irradiating the droplets at said production site. ### Claim 21 (depends on 9) The droplet dispensing device according to claim 9, wherein said nozzle disk is made of a metal or ceramic and comprises a micro-machined nozzle orifice.