Robotic arm, use thereof in pipetting applications and automated pipetting system

Abstract

A robotic arm of an automated pipetting system, comprising: a pipette tip adapter; a slide switch detecting the presence of a pipette tip on the pipette tip adapter, comprising: first and second supports sliding relative to each other along a movement axis between a first and a second position; an electrically conductive contact pad arranged on the first support; an electrically conductive terminal physically contactingly attached to the second support when the supports are in the first position, the terminal being a resilient and intrinsically stable first wiper extending along the movement axis, the first wiper not being in physical contact with the contact pad when the supports are in the second position, an electrical current being flowable between the first wiper and the contact pad when the supports are in the first position, the electrical current between the wiper and the contact pad being interrupted when the supports are in the second position. Use of a robotic arm in an automated pipetting system, the slide switch detecting the presence of a pipette tip on the pipette tip adapter. An automated pipetting system, comprising a robotic arm detecting the presence of a pipette tip on the pipette tip adapter.

Description

Technical Field

[0001] This invention relates to a robotic arm for an automated pipetting system, comprising a pipetting tip adapter and a sliding switch for detecting the presence of a pipetting tip on the adapter. Background Technology

[0002] Electrical switches are ubiquitous and can be found in household appliances, automobiles, and virtually any electrical installation. There are many different types of electrical switches in use, the most common being electromechanical devices comprising one or more sets of movable electrical contacts that allow current to flow between them when in contact. Many specialized forms exist to meet specific needs. In robotics, switches are often used as sensing elements to detect liquid levels, pressure, temperature, or the position of mechanical parts. Such switches need to be small and meet high requirements in terms of lifespan. Reed switches have been widely used as sensing elements in robotics. They are actuated by electromagnetic coils or permanent magnets and return to their initial position when the magnetic field is removed.

[0003] An example of an application for reed switches is their use in detecting the presence of pipette tips on tip adapters in automated pipetting systems (e.g., DE 10 2004 025588). Their size and ability to withstand millions of switching cycles have made reed switches the preferred switches for this application. When a pipette tip is loaded, the magnet moves away from the reed, resulting in the contact breaking.

[0004] However, even at low voltages, reed switches are subject to a significant risk of damage from electrostatic discharge (ESD), leading to maintenance and material costs. Furthermore, reed switches are sensitive to adjacent magnetic fields, such as those used for separating magnetic beads. False closing or opening of the reed triggered by a magnetic field, or damage due to ESD, can disrupt automated pipetting programs and the system itself.

[0005] Therefore, automated pipetting applications, and particularly the detection of pipette tips on robotic arms, have driven the demand for small electrical switches that are ESD-resistant, magnetic field-resistant, and still capable of withstanding millions of switching cycles. Microswitches have proven to be one of the best alternatives to various mechanical switches; however, it has been observed that switching action requires significant force and is not always reliable, and their lifespan is far less than the required millions of switching cycles. Even slide switches, which offer slightly better performance than other types, often rely on springs or quick-acting mechanisms, as disclosed in US 4,012,608 and US 4,191,867. They are susceptible to contact bounce and premature wear. Contact bounce, i.e., bouncing off once or multiple times before stable contact, leads to misinterpretation of the switching pulse, while premature wear causes unintended product failures, resulting in work stoppages, increased maintenance work, and costs. For example, slide switches have been disclosed in US 7,851,714 B2, US 4,376,234, and US 7,220,926 B2, in which a sliding element bridges two contacts in one position but not in another. Even though these switches provide improved switching action, their mechanical resistance remains too high, their lifespan is too short for many robotic applications, and their typical housing and pin structure is incompatible with most instruments, such as those used in automated pipetting systems. Summary of the Invention

[0006] Therefore, the object of this invention is to provide a robotic arm for an automated pipetting system, which has a passive switch (passive switch), i.e., without any external power source. This passive switch detects the presence of a pipette tip on the pipette tip adapter, is unaffected by ESD and external magnetic fields, and has a small size (less than 3.5 × 8 × 11 mm). 3 It exhibits minimal mechanical resistance and the ability to withstand millions of switching cycles during switching operations.

[0007] This problem is solved by a robotic arm with a sliding switch according to the present invention. For example, embodiments can be derived from corresponding preferred embodiments.

[0008] This invention relates to a robotic arm for an automated pipetting system, which includes a slide switch to detect the presence of a pipetting tip on a pipetting tip adapter.

[0009] The robotic arm of the automated pipetting system according to the present invention includes a pipetting tip adapter and a sliding switch for detecting the presence of a pipetting tip on the pipetting tip adapter. The sliding switch includes: a first support member and a second support member configured to slide relative to each other between a first position and a second position along a motion axis; a conductive contact pad disposed on the first support member; and a conductive terminal physically attached to the second support member in physical contact with the contact pad when the support member is in the first position. The terminal is a resilient and inherently stable first wiping member extending along the motion axis, and when the support member is in the second position, the first wiping member is not in physical contact with the contact pad. Current can flow between the first wiping member and the contact pad when the support member is in the first position, but when the support member is in the second position, the current between the wiping member and the contact pad is interrupted, and the current flows in an electrical signal circuit including the contact pad, the first wiping member, a power supply, and an electrical unit.

[0010] The elastic and inherently stable wiping member according to the invention can be a flexible wiper configured such that its pressure on the contact pad does not change significantly when pushed against it, and returns to its initial state when the push is released. The wiping member can be an elongated body, or can be made of two or more substantially parallel elongated bodies, for example, in the form of a brush. One or more elongated bodies extend along the axis of motion, indicating that they are attached to the second support member such that their elongated bodies are positioned substantially parallel to the axis of motion.

[0011] The wiping component must be conductive and therefore includes at least one conductive layer containing one or more conductive materials. Known conductive materials are primarily metals and metal alloys, including silver, copper, gold, aluminum, zinc, nickel, brass, bronze, iron, platinum, carbon steel, lead, and stainless steel, but can also be non-metals such as graphite, conductive polymers, and composites of non-conductive polymers and conductive fillers, such as carbon fiber reinforced polymers or epoxy resins with silver spheres.

[0012] The contact pad according to the invention can be any flat blank or plate that is conductive and therefore comprises one or more conductive layers comprising one or more conductive materials. Thus, the contact pad may comprise one or more of the following materials: silver, copper, gold, aluminum, zinc, nickel, brass, bronze, iron, platinum, carbon steel, lead, stainless chromium-nickel steel, graphite, conductive polymers, and composites of non-conductive polymers and conductive fillers. In one embodiment, the contact pad comprises a surface made of a conductive material that is durable and therefore resistant to abrasion caused by friction from a wiping member. Suitable hard materials may be carbon steel, stainless chromium-nickel steel, vanadium steel, iron, nickel, zinc, brass, copper, platinum, silver, and hard gold; the durability of these materials depends on their treatment, for example, they may be hardened, stretched, cast, or cooled. In one embodiment, the contact pad is formed on a printed circuit board by etching and then plated with hard gold, which is gold alloyed with one or more elements to alter the grain structure of gold to obtain a harder deposited layer. The most commonly used alloying elements in hard gold plating are nickel, cobalt, and iron.

[0013] According to the invention, the first support member can be any electrically isolated solid structure that holds the contact pad and optional skid pad in place. The first support member can be a printed circuit board, or made of one or more electrically insulating materials, such as glass, paper, and polytetrafluoroethylene (PTFE), which have high resistivity, or most plastics.

[0014] According to one embodiment, the first support member includes a conductive material partially or completely coated with an electrical isolation material, such that when the support member slides along the axis of motion to a second position, the current between the first wiping member and the contact pad is interrupted, and in the second position, the first wiping member is in physical contact with the first support member.

[0015] In another embodiment, the first support member is made of a durable material and is therefore resistant to wear caused by friction from the wiping member. The durable material is, for example, glass, PTFE, or a printed circuit board comprising one or more layers, the layers of which may include one of the following materials: paper impregnated with phenolic or epoxy resin, glass fiber fabric impregnated with epoxy resin, aluminum, metal core board or insulating metal substrate (IMS) covered with a thermally conductive thin dielectric, glass and polyester, glass and epoxy resin, PTFE or polyimide.

[0016] The second support member according to the invention can be any electrically insulating solid structure that holds the first wiping member and the second wiping member in place and at a uniform distance from the contact pad. Therefore, the second support member can comprise materials with high resistivity, such as glass, paper, and polytetrafluoroethylene (PTFE), or most plastics.

[0017] According to one embodiment, a conductive, elastic, and inherently stable second wiping member extending along the axis of motion is physically attached to the second support member, the second wiping member being in physical contact with the contact pad (30) such that when the support members (21, 22) are in a first position, current can flow through the contact pad (30) between the first wiping member (41) and the second wiping member (42).

[0018] According to one embodiment, the first support member includes a conductive material partially or completely coated with an electrical isolation material, arranged such that the first wiping member is electrically isolated from the second wiping member, and current can flow between the first wiping member and the second wiping member only when the support member is in a first position, in which both resilient wiping members are in contact with the contact pad.

[0019] The slide switch according to the invention for detecting the presence of a pipette tip on a pipette tip adapter can be used with an electrical signal circuit having a low voltage, for example, 2-5V, and a very small current. According to the invention, the electrical signal circuit is closed when the capacitance measurement of the switch state is >60pF, and open when the capacitance measurement is <5pF. These states can be detected by an electrical detection unit that can transmit the signal to a central processing unit.

[0020] According to one embodiment, the slide switch includes an electrical signal circuit that includes a power supply and an electrical detection unit that can measure resistance and transmit signals to a central processing unit.

[0021] According to one embodiment, the slide switch includes a contact pad disposed on the first support member such that it is at the same horizontal position as the first support member. This allows the wiping member to slide smoothly from one position to another and minimizes wear on the wiping member, the contact pad, and the first support member.

[0022] According to one embodiment, the slide switch includes a contact pad formed on a printed circuit board by etching a copper surface. The resulting contact pad protrudes 20–40 μm above the first support member.

[0023] According to one embodiment, the slide switch includes a contact pad that is attached to the first support member and thus protrudes above the first support member.

[0024] According to one embodiment, the slide switch includes a sweep pad arranged close to but electrically isolated from the contact pad. The contact pad and the sweep pad are spatially separated, forming a gap. The purpose of forming the gap is to electrically isolate the contact pad from the sweep pad. Importantly, the gap should not be too wide to reduce wear on the first support member, the contact pad, and the sweep pad. The material of the gap may be the same as that of the first support member, which may be a printed circuit board, or made or coated with one or more electrically insulating materials. Preferably, it is made of a durable material and thus resistant to wear caused by friction from the wiping member. Durable materials include, for example, glass, polytetrafluoroethylene (PTFE), or a printed circuit board comprising one or more layers, the layers of which may include one of the following materials: paper impregnated with phenolic or epoxy resin, fiberglass fabric impregnated with epoxy resin, aluminum, a metal core board, or an insulating metal substrate (IMS) coated with a thermally conductive thin dielectric, glass and polyester, glass and epoxy resin, PTFE, or polyimide.

[0025] According to one embodiment, the slide switch includes a sweep pad arranged close to the contact pad, and both the sweep pad and the contact pad are flat. They may protrude above the first support member.

[0026] According to one embodiment, the slide switch includes a sweep pad arranged close to the contact pad to form a spacer, the spacer including solder resist to further reduce wear on the first wiping member, the contact pad, and the sweep pad. According to another embodiment, the slide switch includes a sweep pad arranged close to the contact pad to form a spacer, the spacer including one or more additional sweep pads. This results in less wear on the first wiping member, the contact pad, and the sweep pad without reducing the width of the spacer, which would otherwise cause bridging between the sweep pad and the contact pad.

[0027] According to one embodiment, the slide switch includes one or more sweep pads arranged close to the contact pad, wherein the surface of the contact pad, the one or more sweep pads, and the spacer are flat. This allows the wiping member to slide smoothly from one position to another and minimizes wear on the wiping member, the contact pad, the one or more sweep pads, and the spacer.

[0028] According to one embodiment, the external dimensions of the slide switch are small enough to fit into any robotic application, particularly into tip adapters for automated pipetting applications, i.e., external dimensions less than 3.5 × 8 × 11 mm. 3 .

[0029] According to one embodiment, the slide switch can be used with an actuation mechanism, such as a spring-loaded pusher, for releasing the pipette tip. The actuation mechanism in the tip adapter for automated pipetting applications can be a spring-loaded pusher, wherein, in the closed position, the spring force can be between 0.3N and 1.5N, more preferably between 0.6N and 1.2N, and the sliding distance can be between 2mm and 10mm, more preferably between 5mm and 7mm. The slide switch can be disengaged when the spring is released; however, in embodiments of the tip adapter for automated pipetting applications, the slide switch is closed when the spring is released.

[0030] Although the foregoing invention has been described in some detail for illustrative purposes, it will be apparent to those skilled in the art that changes and modifications can be made within the scope of this invention.

[0031] According to the solution of the present invention, the following advantages are particularly achieved, at least in the preferred embodiments:

[0032] Slide switches utilize contacts with a wiping action. This ensures a clean surface and allows for fairly high contact pressure, yet still presents minimal mechanical resistance during switching operation. This results in long-term resistance to dust, potentially several years in a laboratory environment.

[0033] Another advantage comes from the simple structure made of only a few parts, which allows for a size smaller than 3.5×8×11mm. 3 Its compact, space-saving design makes it easy to use in any small application.

[0034] In one embodiment, a conductive and resilient second wiping member is physically attached to a second support member such that the second wiping member is in physical contact with a contact pad, and when the support member is in a first position, current can flow through the contact pad between the first and second wiping members, in which both electrical contacts are on the wiping member. By avoiding the requirement that one contact must be mounted on the sliding portion while the other is on the fixed portion, the slide switch will be more durable, and due to simpler wiring and the absence of any moving or bent wires and shifting solder joints, the slide switch can potentially withstand millions of switching cycles.

[0035] Furthermore, the slide switch according to the invention does not use any magnet, thus preventing erroneous closing or opening and is not damaged by external magnetic fields from larger electromagnetic coils or permanent magnets. This allows the slide switch to be used close to a magnet without the risk of interference. An example of such an application is for detecting the presence of pipette tips on tip adapters in automated pipetting systems, where these tip adapters may be close to a magnetic field, such as for magnetic bead separation.

[0036] Thus, the slide switch according to the invention is more reliable, safer, and cheaper, for example, by avoiding indirect costs such as abandoning automated pipetting experiments or damage to robots.

[0037] The slide switch according to the invention also resists electrostatic discharge (ESD), thereby preventing its destruction and disruption of automated pipetting experimental plans and the system itself.

[0038] Furthermore, the slide switch according to the invention, which converts mechanical motion into electrical signals, is a passive switch (passive switch) and therefore does not use any external power source.

[0039] These improvements combined also make the slide switch resistant to important chemicals frequently used around robots and automated pipetting systems, such as cleaning fluids, ethanol, and isopropanol. The slide switch according to the invention has been proven to resist up to 7 days in the saturated vapors of any of the following: water, DMSO, ethanol, methanol, n-hexane, acetone, chloroform, 5M hydrochloric acid, 1M sodium hydroxide, and 5% sodium hypochlorite (bleach).

[0040] Due to its simple principle and material selection, it can also operate reliably over a wide temperature range, preferably at 15–32°C and 30–80% relative humidity, and can be stored at -20°C to +60°C and 20–80% relative humidity.

[0041] In summary, the slide switch according to the present invention will therefore have a longer service life compared to other micro switches, and will exhibit high reliability in the correct switching state during use and after several years of long-term storage, thereby making it safer, resulting in less work and lower operating costs.

[0042] Furthermore, the advantages and convenience of the present invention arise from the following description of embodiments based on the accompanying drawings. Attached Figure Description

[0043] The invention will be described in detail with reference to the accompanying drawings, which schematically depict embodiments of the invention. Specifically:

[0044] Figure 1a A full cross-sectional schematic diagram of the slide switch according to the invention in the first position is shown; and

[0045] Figure 1b It is shown in the second position, Figure 1a A full cross-sectional view of the slide switch shown; and

[0046] Figure 2a A full cross-sectional schematic diagram of a slide switch with a second wiping member according to the invention in a first position is shown; and

[0047] Figure 2b It is shown in the second position, Figure 2a A full cross-sectional view of the slide switch shown; and

[0048] Figure 3a A full cross-sectional schematic diagram of a slide switch with a sweep pad according to an embodiment of the present invention in a first position is shown; and

[0049] Figure 3b It is shown in the second position, Figure 3a A full cross-sectional schematic diagram of a slide switch with a sweep pad shown; and

[0050] Figure 4a A full cross-sectional schematic diagram of a slide switch with a swipe pad and electrical signal circuit according to an embodiment of the present invention, having two wiping components, is shown; and

[0051] Figure 4b A full cross-sectional schematic diagram of a slide switch with a wiping member, according to an embodiment of the invention, including a sweep pad and electrical signal circuitry, is shown; and

[0052] Figure 5a The arrangement of the contact pads and skid pads on the first support member according to an embodiment of the present invention is shown; and

[0053] Figure 5b A full cross-sectional schematic diagram of a slide switch with two sweep pads according to an embodiment of the invention in a second position is shown; and

[0054] Figure 6 A schematic exploded view of the lower portion of a robotic arm in an automated pipetting system is shown. The automated pipetting system includes a pipette tip adapter and a sliding switch according to an embodiment of the invention for detecting the presence of a pipette tip; and

[0055] Figure 7 A schematic side view of the lower portion of a robotic arm of an automated pipetting system according to an embodiment of the present invention is shown before (left) and after (right) picking up a pipette tip. The automated pipetting system includes a slide switch and a pipette tip adapter. Detailed Implementation

[0056] Figure 1a A full cross-sectional schematic diagram of the slide switch 10 according to the invention in the first position is shown.

[0057] The slide switch 10 shown here includes a first support member 21 and a second support member 22 configured to slide relative to each other between a first position and a second position along a motion axis 110 shown in dashed lines. A terminal 40, in the form of a resilient and inherently stable first wiping member 41, is physically attached to the second support member 22 and makes physical and electrical contact with a conductive contact pad 30 when the slide switch 10 is in the first position shown. The purpose of the second support member 22 is to hold the first wiping member 41 in place and at a uniform distance from the first support member 21. The contact pad 30 must be conductive at least on its surface so that current can flow between the first wiping member 41 and the contact pad 30 when the support members 21, 22 are in the first position shown. The contact pad 30 may be mounted on the first support member 21 or may be formed on a printed circuit board by etching. In the illustrated embodiment, the contact pad 30 protrudes above the first support member 21.

[0058] Figure 1b It is shown in the second position, Figure 1a The diagram shows a full cross-sectional view of the slide switch. As shown, when the support members 21 and 22 are in the second position, the first wiping member 41 is not in physical contact with the contact pad 30. Instead, the first wiping member 41 is in physical contact with the first support member 21, which comprises one or more electrically insulating materials, such as glass, paper, polytetrafluoroethylene, or plastic. As a result, when the support members 21 and 22 are in the second position as shown, no current can flow between the first wiping member 41 and the contact pad 30.

[0059] Figure 2a A full cross-sectional view of a slide switch 10 according to the invention in a first position is shown. The slide switch 10 shown here includes: a first support member 21 and a second support member 22 configured to slide relative to each other between a first position and a second position along a motion axis 110 shown in dashed lines; and a contact pad 30 attached to the first support member 21 or as an integral part thereof. Terminals 40 in the form of a resilient first wiping member 41 and a resilient second wiping member 42 are physically attached to the second support member 22 and contact the contact pad 30 when the slide switch 10 is in the first position shown. According to the invention, when the support members 21, 22 are in the first position shown, current can flow between the first wiping member 41 and the contact pad 30. In the illustrated embodiment, when the support members 21, 22 are in the first position shown, current can flow through the contact pad 30 between the first wiping member 41 and the second wiping member 42.

[0060] The purpose of the second support member 22 is to hold both wiping members 41, 42 in place and at a uniform distance from the first support member 21. The material of the second support member 22 must be electrically insulating so that it does not electrically connect the first wiping member 41 to the second wiping member 42. Instead, the contact pad 30 must be conductive at least on its surface so that current can flow between the first wiping member 41 and the contact pad 30 when the support members 21, 22 are in the first position shown. The contact pad 30 may be mounted on the first support member 21 or formed on a printed circuit board by etching. In the illustrated embodiment, the contact pad 30 protrudes above the first support member 21.

[0061] Figure 2b It is shown in the second position, Figure 2a The diagram shows a full cross-section of the slide switch.

[0062] In the illustrated embodiment, when the support members 21 and 22 are in the second position shown, only the resilient second wiping member 42 is in contact with the contact pad 30. The first wiping member 41 disconnects from the contact pad 30 and becomes physically in contact with the first support member 21, which comprises one or more electrically insulating materials. As a result, when the support members 21 and 22 are in the second position shown, no current can flow between the first wiping member 41 and the contact pad 30.

[0063] Figure 3aA full cross-sectional view of a slide switch 10 with a sweep pad 50 according to an embodiment of the invention in a first position is shown. The slide switch 10 shown here includes a first support member 21 and a second support member 22 configured to slide relative to each other along a motion axis 110 shown in dashed lines between a first position and a second position. Terminals 40 in the form of a resilient first wiping member 41 and a resilient second wiping member 42 are physically attached to the second support member 22 and contact a contact pad 30 when the slide switch 10 is in the first position shown. The contact pad 30 may be mounted on the first support member 21 or may be formed on a printed circuit board by etching. In the illustrated embodiment, the contact pad 30 protrudes above the first support member 21. The contact pad 30 must be conductive at least on its surface so that current can flow between the first wiping member 41 and the contact pad 30 when the support members 21, 22 are in the first position shown. In the illustrated embodiment, when the support members 21, 22 are in the first position shown, current can flow through the contact pad 30 between the first wiping member 41 and the second wiping member 42. The contact pad 30 can be mounted on the first support member 21 or formed on a printed circuit board by etching. In the illustrated embodiment, the contact pad 30 and the sweep pad 50 protrude above the first support member 21 and are flat.

[0064] Figure 3b It is shown in the second position, Figure 3a The diagram shows a full cross-sectional view of a slide switch 10 with a sweep pad 50. As shown, when the support members 21, 22 are in the second position, the first wiping member 41 is not in physical contact with the contact pad 30. Instead, the first wiping member 41 is in physical contact with the sweep pad 50. The contact pad 30 and the sweep pad 50 are spatially separated, forming a spacer 60. According to the invention, the spacer 60 may include solder resist. Furthermore, the first support member 21 may include one or more additional sweep pads 50. As shown in FIG. 5, this may take the form of a protective element in the spacer 60. According to the invention, the sweep pad 50 is electrically isolated from the contact pad 30, and when the support members 21, 22 are in the second position as shown, no current can flow between the first wiping member 41 and the contact pad 30.

[0065] Figure 4aA full cross-sectional view of a slide switch 10 with two terminals 40, a swipe pad 50, and an electrical signal circuit according to an embodiment of the present invention is shown, wherein support members 21, 22 are in a first position. Terminals 40, in the form of a resilient first wiping member 41 and a resilient second wiping member 42, are physically attached to a second support member 22 and contact a contact pad 30 when the slide switch 10 is in the first position shown. According to the present invention, in the first position shown, current can flow between the first wiping member 41 and the contact pad 30. In the illustrated embodiment, current can flow between the first wiping member 41 and the second wiping member 42 through the contact pad 30. When the support members 21, 22 are in the first position shown, the electrical signal circuit, including a power supply 70 and an electrical detection unit 80, is thus closed.

[0066] Figure 4b A full cross-sectional view of a slide switch 10 with a terminal 40, a swipe pad 50, and an electrical signal circuit according to an embodiment of the present invention is shown, wherein support members 21, 22 are in a first position. The terminal 40, in the form of a resilient first wiping member 41, is physically attached to the second support member 22 and contacts the contact pad 30 when the slide switch 10 is in the first position shown. According to the present invention, in the first position shown, current can flow between the first wiping member 41 and the contact pad 30. The electrical signal circuit, including a power supply 70 and an electrical detection unit 80, is thus closed.

[0067] Figure 5a The arrangement of contact pads 30 and skid pads 50 on a first support member 21 according to an embodiment of the present invention is shown. The contact pads 30 and one or more skid pads 50 are spatially separated, forming one or more spacers 60. The purpose of forming the spacers 60 is to electrically isolate the contact pads 30 from the one or more skid pads 50. At the same time, it is important that the spacers 60 are not too wide to reduce wear on the first support member 21, one terminal 40 in the form of a resilient first wiping member 41, and another terminal 40 in the form of a resilient second wiping member 42. To further reduce the width of the spacers without the risk of bridging the individual pads, two or more skid pads 50 can be used, one of which is spatially separated between the contact pads 30 and the skid pads 50, as shown below. Figure 5a As can be seen in the two lower examples. As shown here, the spacer 60 can be arranged in a straight line perpendicular to or at any angle to the contact pad 30, or can have any other shape that minimizes the force that must be applied to the resilient first wiping member to cross the spacer. The spacer is typically made of the same material as the first support member 21, which can be the material of a printed circuit board or any other electrical isolation material. To further reduce wear, the spacer 60 may include solder resist.

[0068] Figure 5b A full cross-sectional view of a slide switch 10 with two sweep pads 50 according to an embodiment of the present invention is shown. The sweep pads 50 are arranged close to but electrically isolated from the contact pad 30, thereby forming two spacers 60. The spacers 60 electrically isolate the contact pad 30 from one or more sweep pads 50. At the same time, it is important that the spacers 60 are not too wide to reduce wear on the first support member 21, one terminal 40 in the form of a resilient first wiping member 41, and the other terminal 40 in the form of a resilient second wiping member 42.

[0069] As shown in the figure, when the support members 21 and 22 are in the second position, the first wiping member 41 contacts the sliding pad 50 and disconnects from the contact pad 30. As a result, no current can flow between the first wiping member 41 and the contact pad 30.

[0070] In the embodiment shown here, the surfaces of the contact pad 30 and the skid pad 50 are flat.

[0071] Figure 6 A schematic exploded view of the lower portion of a robotic arm 100 of an automated pipetting system is shown. The automated pipetting system includes a pipetting tip adapter 90 and a slide switch 10 according to an embodiment of the invention for detecting the presence of a pipetting tip 120 on the pipetting tip adapter 90.

[0072] The slide switch 10 shown here includes: a first support member 21 configured to slide between a first position and a second position, comprising a contact pad 30 disposed on the first support member 21; and a first wiping member 41 and a second wiping member 42, both of which are resilient, and when the first support member 21 is in the first position, the first wiping member 41 and the second wiping member 42 are in contact with the contact pad 30 such that current can flow between the first wiping member 41 and the contact pad 30, and current can flow between the first wiping member 41 and the second wiping member 42 through the contact pad 30, and such that when the first support member 21 slides to the second position, the first wiping member 41 disconnects from the contact pad 30, and in the second position, no current can flow between the first wiping members 41.

[0073] Here, the first support member 21 includes a sweep pad 50 arranged close to but electrically isolated from the contact pad 30. The contact pad 30 and the sweep pad 50 are spatially separated, forming a spacer 60. According to the invention, the spacer 60 may include solder resist. Furthermore, the first support member 21 may include one or more additional sweep pads 50, which may be placed in the spacer 60 as protective elements (not shown). A first wiping member 41 and a second wiping member 42 are physically attached to a second support member 22, which holds the two wiping members in place and at a uniform distance from the contact pad 30 and the sweep pad 50. The material of the second support member 22 must be electrically insulating so that it does not electrically connect the first wiping member 41 to the second wiping member 42. Instead, the contact pad 30 must be conductive at least on its surface to allow an electrical signal circuit to close when the first support member 21 is in a first position and to allow an electrical signal circuit to open when the first support member 21 is in a second position.

[0074] Figure 7 A schematic side view of the lower portion of a robotic arm 100 of an automated pipetting system according to an embodiment of the present invention is shown before (left) and after (right) picking up a pipette tip 120. The automated pipetting system includes a slide switch 10 and a pipette tip adapter 90. The slide switch 10 shown here includes a first support member 21 and a second support member 22 configured to slide relative to each other between a first position and a second position along a motion axis 110 shown in dashed lines. The slide switch 10 shown on the left is in the first position, which corresponds to the idle position of the pipette tip adapter 90 when no pipette tip 120 is installed. In this position, current can flow between a first wiping member 41 (not shown) and a contact pad 30 (not shown), and an electrical signal circuit including a power supply 70 and an electrical detection unit 80 is closed. When the pipette tip 120 is picked up, the first support member 21 slides relative to the second support member 22 from the first position to the second position. This displacement is indicated by dashed lines and arrows. The right side shows a pipette tip adapter 90 on which a pipette tip 120 is mounted. In this case, the slide switch 10 is in the second position, in which, according to the invention, no current can flow between the first wiping member 41 (not shown) and the contact pad 30 (not shown), and the electrical signal circuit including the power supply 70 and the electrical detection unit 80 is disconnected.

[0075] Incidentally, it is also possible to implement the invention with various variations on the examples and aspects of the invention shown herein that have been the focus of the foregoing.

[0076] List of reference numerals

[0077] 10 Slide Switch

[0078] 21 First Support Component

[0079] 22 Second support member

[0080] 30 Contact pad

[0081] 40 terminals

[0082] 41 Elastic first wiping component

[0083] 42. Elastic second wiping component

[0084] 50 Sweep Pads

[0085] 60-section

[0086] 70 power supply

[0087] 80 Electrical Testing Units

[0088] 90 Pipette Tip Adapter

[0089] 100 robotic arms

[0090] 110 Motion axis

[0091] 120 pipette tips

Claims

1. A robotic arm (100) of an automated pipetting system, the robotic arm (100) comprising: a pipette tip adapter (90); and a switch attached to the pipette tip adapter (90) for detecting the presence of a pipette tip (120) on the pipette tip adapter (90), characterized in that the switch is a slide switch (10) comprising: a first support member (21) and a second support member (22) configured to slide relative to each other along a movement axis (110) between a first position and a second position when a pipette tip (120) is mounted on or detached from the pipette tip adapter (90); an electrically conductive contact pad (30) arranged on the first support member (21), and the first position of the first support member (21) and the second support member (22) is defined by an electrically conductive terminal (40) physically attached to the second support member (22) and in physical contact with the contact pad (30), whereas the terminal (40) is a resilient and stable first wiping member (41) stretching along the movement axis (110), and, the second position of the first support member (21) and the second support member (22) is defined when the first wiping member (41) is not in physical contact with the contact pad (30), and, when the first support member (21) and the second support member (22) are in the first position, an electrical current can flow between the first wiping member (41) and the contact pad (30), when the first support member (21) and the second support member (22) are in the second position, the electrical current between the first wiping member (41) and the contact pad (30) is interrupted, and, the electrical current flows in an electrical signal circuit comprising the contact pad (30), the first wiping member (41), a power supply (70) and an electrical unit (80).

2. The robotic arm (100) according to claim 1, characterized in that an electrically conductive resilient and stable second wiping member (42) stretching along the movement axis (110) is physically attached to the second support member (22), the second wiping member (42) is in physical contact with the contact pad (30) such that when the first support member (21) and the second support member (22) are in the first position, an electrical current can flow between the first wiping member (41) and the second wiping member (42) through the contact pad (30).

3. The robotic arm (100) according to claim 2, characterized in that the second support member (22) electrically isolates the first wiping member (41) from the second wiping member (42).

4. The robotic arm (100) according to claim 1, characterized in that The first support member (21) comprises at least one glide pad (50) arranged on the first support member (21), the glide pad (50) being proximate to the contact pad (30) but electrically isolated from the contact pad (30) by a spacer (60) such that the first wiping member (41) is in contact with the glide pad (50) when the first support member (21) and the second support member (22) are in the second position.

5. The robot arm (100) according to claim 4, wherein The first support member (21) comprises more than one glide pad (50).

6. The robot arm (100) according to claim 4 or 5, wherein The spacer (60) comprises a solder resist.

7. The robot arm (100) according to claim 4 or 5, wherein The surface of the contact pad (30) and the at least one glide pad (50) is flat.

8. The robot arm (100) according to claim 6, wherein The surface of the contact pad (30) and the at least one glide pad (50) is flat.

9. The robot arm (100) according to any one of claims 1 to 5, wherein The first support member (21) comprises a printed circuit board.

10. The robot arm (100) according to any one of claims 1 to 5, wherein The first support member (21) and the second support member (22) comprise one or more electrically insulating materials.

11. The robot arm (100) according to any one of claims 1 to 5, wherein The first support member (21) and the second support member (22) comprise one or more of the following materials: glass, paper, plastic.

12. The robot arm (100) according to any of claims 1 to 5, characterized in that, The first support member (21) and the second support member (22) comprise polytetrafluoroethylene.

13. The robot arm (100) according to any one of claims 1 to 5, wherein The electrically conductive contact pad (30) comprises one or more layers of electrically conductive material, the electrically conductive material comprising one or more of the following: carbon steel, stainless steel, chromium-nickel steel, vanadium steel, iron, nickel, zinc, brass, copper, platinum, silver, hard gold.

14. Use of a robot arm (100) according to any one of claims 1 to 13 in a pipetting application, wherein The slide switch (10) detects the presence of a pipette tip (120) on a tip adapter (90) in an automated pipetting system.

15. An automated pipetting system comprising a robot arm (100) according to any one of claims 1 to 13.

16. The automated pipetting system according to claim 15, wherein The robot arm (100) detects the presence of a pipette tip (120) on a tip adapter (90).

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